Fwd: Paper Request

Posted by Bobby on
———- Forwarded message ———-
From: Atilla Çelik <dratillacelik@yahoo.com>
Date: Sun, Sep 21, 2008 at 3:43 PM
Subject: Paper Request
To: drhsdas@gmail.com

Dear Dr. Das.
I am Dr. Atilla Celik, from Istanbul, Turkey.
I am working at "Haydarpasa Numune Training & Research Hospital" as a General Surgeon.
I have seen your blog in recently. If it possible, I want to a copy of your published article that named "Large Adrenal Pseudocyst: Case Report with Review of Literature" in PDF format because of to cited our article "Laparoscopic management of giant adrenal cyst : Case report".
Best wishes from Turkey.
Dr. Atilla Celik.
General Surgeon.
Haydarpasa Numune Training & Research Hospital
2nd Department of General Surgery
Istanbul, Turkey.
+90 216 5652728 (Home)
+90 532 4865625 (Cell)
 

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Japanese Encephalitis

Posted by Bobby on

JE

 

 

 

 

**Child with fever & altered sensorium with symptoms developing developing acutely

 

Japanese encephalitis is a disease caused by the mosquito-borne Japanese encephalitis virus. The Japanese encephalitis virus is a virus from the family Flaviviridae. Domestic pigs and wild birds are reservoirs of the virus; transmission to humans may cause severe symptoms. One of the most important vectors of this disease is the mosquito Culex tritaeniorhynchus. This disease is most prevalent in Southeast Asia and the Far East.

 

 

 

 

 

Japanese encephalitis has an incubation period of 5 to 15 days and the vast majority of infections are asymptomatic: only 1 in 250 infections develop into encephalitis.

 

Severe rigors mark the onset of this disease in humans. Fever, headache and malaise are other non-specific symptoms of this disease which may last for a period of between 1 and 6 days. Signs which develop during the acute encephalitic stage include neck rigidity, cachexia, hemiparesis, convulsions and a raised body temperature between 38 and 41 degrees Celsius. Mental retardation developed from this disease usually leads to coma. Mortality of this disease varies but is generally much higher in children. Transplacental spread has been noted. Life-long neurological defects such as deafness, emotional lability and hemiparesis may occur in those who have had central nervous system involvement. In known cases some effects also include nausea, headache, fever, vomiting and sometimes swelling of the testicles.

 

The causative agent Japanese encephalitis virus is an enveloped virus of the genus flavivirus and is closely related to the West Nile virus and St. Louis encephalitis virus. Japanese Encephalitis is diagnosed by detection of antibodies in serum and CSF (cerebrospinal fluid) by IgM capture ELISA.Infection with JEV confers life-long immunity. All current vaccines are based on the genotype III virus.

 

 

Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia, with 30,000–50,000 cases reported annually. Case-fatality rates range from 0.3% to 60% and depends on the population and on age. Rare outbreaks in U.S. territories in Western Pacific have occurred. The natural host of the Japanese encephalitis virus is bird, not human, and many believe the virus will therefore never be completely eliminated

 

LIST OF OPEN SOURCE SOFTWARES

Posted by Bobby on
A Bold GNU Head

                   LIST OF OPEN SOURCE SOFTWARES


          Categories

                        Public Health and Bio surveillance

Electronic health or medical record

  • CHITS Community Health Information Tracking System – EHR for public health community centres in developing countries
  • ClearHealth Clearhealth – Flexible and standards compliant EMR/EHR
  • ElementalClinic – open source web-based EMR for mental health written in Perl, licensed under the GPL. Also available as a hosted service.
  • FreeMedForms – open source (c++/Qt4.5) highly dynamic EMR. FreeMedForms is released under the BSD license and is intended to be fully internationalized.
  • GNUmed is a WxPython application that uses PostGreSQL.
  • FFEHR Free Feathers Electronic Health Record – EHR application developed using the Mozilla programming framework. FFEHR can run independently or within the Firefox browser.
  • HealthForge – a .Net e-health groupware solution with EMR, Practice Management and patient/physician connectivity. Built on the popular DotNetNuke framework.
  • Hospital OS Open source hospital information system in Thai
  • HOSxP
  • Indivo – open source, personally controlled health record system that enables patients to own complete, secure copies of their medical records. Powers the Dossia framework
  • Medical a multi-user, highly scalable, centralized Electronic Medical Record (EMR) and Hospital Information System (HIS) for openERP
  • OpenEHR Inter-operable, implementation independent Health Record Specifications [1]
  • OpenEMR an open-source Electronic Medical Record (EMR) software.
  • Open Healthcare
  • OpenMRS is a community-developed, open-source, enterprise EMR framework. Extensible and scalable EMR based on Java.
  • OpenVista is a VistA-based distribution with a cross-platform, GTK/C# based clinical front-end. Both client and server are licensed under the AGPL. Reference deployments in a range of small and large facilities.
  • OSCAR McMaster an open-source Electronic Medical Record (EMR) software. The billing component of the software is specialized for the needs of the Canadian health care providers.
  • PatientOS a rich client open-source EMR designed to evolve to a healthcare information system.
  • SmartCare
  • Tolven Healthcare
  • TORCH – Easy to install and customize EMR application in Python
  • VistA — Veterans Administrations integrated Electronic Health Record and Electronic Image Record system available for non-governmental use on MUMPS licensed systems as WorldVistA.
  • ZEPRS The ZEPRS application is an electronic patient record system that enables clinicians to enter data from patient visits using a web browser.
  • Care2x Hospital information system/practice management system/EHR
  • ClearHealth ClearHealth covers the five major areas of practice operations including scheduling, billing, EMR, HIPAA Security and accounts receivable. It offers a fully comprehensive system which now offers tools like E-Prescribing, Drug Interactions, Electronic Labs and Lab ordering. It is the largest open source healthcare solution serving more than 500 sites including the Primary Care Coalition network in MD with 50 sites and around 100,000 patients.
  • FreeDiams – open source (c++/Qt4.5) prescriber and drugs interactions tester. FreeDiams is released under the BSD license and is intended to be fully internationalized but for now drugs database and interactions database are only available in french.
  • FreeMED is a practice management and electronic and computer records system. It allows the tracking of medical data, in detail, with preservation not just of the diagnosis but the reasons for medical encounters. FreeMED is released under the LGPL GNU license. FreeMED is an HIPAA compliant FOSS Practice Management System that handles billing.
  • MedinTux MedinTux is a French medical practice management system, with a web interface as well as a desktop one, that has been initially to manage a hospital emergency department. Being very modular, it has been extended to run also many different smaller practices. It works on GNU/Linux, Mac OS X, Microsoft Windows
  • MirrorMed MirrorMed is a free and open source EHR and practice management system written in PHP. MirrorMed is a web-based application that is capable of running a healthcare practice. MirrorMed shares code with FreeMED, and OpenEMR. MirrorMed is primarily sponsored by SynSeer.
  • Office Manager Encompassing office management healthcare software for medical practices, doctors groups, DMEs, retailers, etc. It does User/patient management, point of sale, scheduling, sign-in, inventory, insurance claims, accounting, etc. Any OS!
  • Open Dental Dental practice management software wiki article Open dental
  • OpenEMR (see also the OpenEMR wikipedia article)
  • OpenTAPAS Technology Assisted Practice Application Suite (TAPAS) is a term that describes digital tools that assist physicians deliver care in a paper based office
  • Elexis Praxisprogramm is an Eclipse RCP program for all aspects of a medical practice: electronic medical record (EMR), laboratory findings etc., as well as accounting, billing (Swiss TARMED-System, other systems to be developed) and other daily work
  • DHIS Open-source district health management information system and data warehouse (license: BSD license)
  • iHRIS Suite Open source platform for management of human resources for health developed by IntraHealth International and funded by USAID (license: GPLv3)
  • 3D SlicerMedical Visualization and Processing Environment for Research
  • Amide tool for viewing, analyzing, and registering volumetric medical imaging data sets, actively being developed
  • BioImageXD software for analysis, processing and 3D rendering of multi dimensional, multi data channel, time series image data from microscopy and other sources
  • BrainStorm an electro/magnetoencephalography (EEG/MEG) data processing and vizualisation toolbox.
  • BrainVisa a brain imaging package including data processing and visualization capabilities, such as T1-based gyrus segmentation, diffusion-based fibertracking, PET, MEG, EEG and more.
  • CDMedic PACS
  • ClearCanvas Workstation is an open source DICOM workstation and application framework for developing medical imaging applications.
  • CTSIM Computed Tomography Simulator, active development
  • DCM4CHE Open Source Clinical Image and Object Management written in java
  • DCMTK is a collection of libraries and applications implementing large parts the DICOM standard
  • DeVIDE is the open source (BSD-style license) and cross-platform (Windows, Linux) Delft Visualization and Image processing Development Environment, a visual programming system focused on medical visualization and image processing. DeVIDE incorporates VTK, ITK, numpy, matplotlib, DCMTK and GDCM. Latest features include a visual DICOM browser.
  • Dicom4j An open source DICOM Java framework.
  • Dicom4j-apps Free and open-sources DICOM applications in Java.
  • DICOM Router a variety of DICOM related utilities
  • DICOM Validation Tool (DVT) is a software utility and a set of .NET components that will assist in testing the medical / healthcare protocol DICOM. DVT provides you the methods to transfer and validate DICOM objects.
  • Drishti is a volumetric visualisation package for viewing Computer Tomography data. Able to import DICOM image stacks.
  • ecg2png Program designed to convert scanned 12-lead electrocardiograms into PNG format
  • Endrov Image and data viewer and editor
  • Eviewbox Java medical imaging software
  • GDCM Grassroots DiCoM is a C++ library for DICOM medical files. It is automatically wrapped to python/C#/Java (using swig). It supports RAW,JPEG (lossy/lossless), J2K,JPEG-LS,RLE and deflated. It also comes with DICOM Part 3,6 & 7 of the standard as XML files.
  • Imlib3d C++ library for 3D (volumetric) image processing
  • ITK Segmentation and Registration Toolkit
  • ITK-SNAP Interactive software for 3D image navigation, annotation and automatic segmentation
  • kradview Free (GPL) DICOM viewer, for Linux and FreeBSD.
  • METK is an open source toolkit to visualize and explore medical datasets.
  • Miniwebpacs storage, control and recovery of medical images and information in healthcare providers of small and medium capacity. Such system is based on the DICOM standard and in the actual WEB technologies.
  • MITK Medical Imaging Interaction Toolkit
  • NIRFAST NIRFAST is an open source FEM based software package designed for modeling Near Infrared Frequency domain light transport in tissue.
  • O3-RWS is the Radiology Workstation of the Open Three ( O3 ) Consortium. According to the IHE definitions, O3-RWS is an Open Source, DICOM based, Internationalized, Modular and Portable Image Display actor plus the integration of several other IHE actors.
  • OsiriX – [3] 3D DICOM Medical Viewer for Mac OS X. Complete DICOM Viewer with DICOM network support
  • Ogles is a three-dimensional volume and slice data visualization tool
  • Opensource PACS Wet Read system includes: image order, image reconciler, radiologist workstation (DICOM viewer), DICOM structured reporting, web-based summary of patient diagnosis. (see Projects under Navigation box)
  • ParaView Large Scale Visualization tool
  • PhP Nuke healthcare PHP-Nuke based system for Health Institutes. X-Ray and Register modules for storing patient data with pictures. System is DICOM compatible
  • Tempo(Topographic Eeg Mapping PrOgram) is open source software for 3D visualization of brain electrical activity
  • Virtual PACS allows radiologists to use a DICOM workstation to access multiple DICOM repositories as a single federated virtualized PACS. The DICOM repositories are exposed on caGrid and can include PACS, image archives such as National Cancer Imaging Archive or other DICOM data warehouses.
  • Voreen stands for Volume Rendering Engine. It is a library providing essential functionality for visually exploring volume data sets. Voreen supports most relevant data formats as for instance DICOM and is currently used in medical visualization as well as for visualizing electron microscopy data.
  • VTK Visualization Toolkit
  • Xebra (medical imaging software)
  • Blood_collection is a Web based software to increase the number of donors in blood collections by managing slots for registrations, with a front-end to delegate the blood collection creation and administration (license: GPL)
  • Caisis is a web based information system for the storage and analysis of cancer patient data intended to bridge the gap between clinic and research (license: GPL)
  • OpenClinica is a web-based application that facilitates electronic data capture in clinical trials. The system is free but commercial support is available (license: LGPL)
  • Open Infrastructure for Outcomes (OIO) system enables clinicians, researchers, and other non-programmers to create and maintain flexible and portable patient/research records
  • OpenMEDIS is a simple, flexible, and standardized Web based tool to collect and process information on health technology infrastructure in low- and middle income countries (license: GPL)
  • Resmedicinae Open source medical information system for GPs (license: GPL)
  • trilonis-mc For managed healthcare group eligibility, billing, capitation, and claims adjudication. Aimed at TPAs, HMOs, PPOs, and self-insured employers. HIPAA compliant. Will handle medical, dental, vision, psych, section 125 and COBRA (license: GPL)
  • Mural Project The Open Source Mural Project from Sun is a robust Master Index. It can be configured as a Master Patient Index, Master Provider Index, or any other Index. Fully extensible and configurable. Many existing installations prove scalability and functionality. By making use of the available PIX/PDQ implementation (http://kenai.com/projects/healthcaresolutions), it is IHE Comliant. Commercial licensing and support are available.
  • HAPI (HL7 application programming interface; pronounced “happy”) is an open-source, object-oriented HL7 2.x parser for Java
  • nHAPI .Net version of HAPI (http://hl7api.sourceforge.net/)
  • HL7 Inspector 2 HL7 analysis and validation tool
  • O3-DPACS stands for “Open Three ( O3 ) – Data & Picture Archiving and Communication System”. O3-DPACS is a DICOM & HL7 based IHE compliant Open Source PACS extended to any type of data
  • Open LIS-HL7 HL7 library written in Delphi 6, last updated in 2002
  • ProtoGen/HL7 an implementation of HL7 in C++, last updated in 2001
  • hl7lib Software implementing Health Level 7 protocols commonly used in the medical industry, last released in the year 2000
  • HL7ImExa is table driven set C routines to encode/decode HL-7 messages, last updated in 1996
  • BioSig library for biomedical signal processing featuring, for example, the analysis of biosignals such as the electroencephalogram (EEG), electrocorticogram (ECoG), electrocardiogram (ECG), electrooculogram (EOG), electromyogram (EMG), respiration, and so on License: GPL
  • ecg2png Program designed to convert scanned 12-lead electrocardiograms into PNG format
  • BioMail is a small web-based application for medical researchers, biologists, and anyone who wants to know the latest information about a disease or a biological phenomenon. It is written to automate searching for recent scientific papers in the PubMed Medline database
  • caGrid is an underlying service oriented infrastructure that supports caBIG, an initiative of the National Cancer Institute
  • Jumper 2.0 is a Science 2.0 technology that uses knowledge tags to capture knowledge about data in remote data stores. It collects these in tag profiles that are stored in a Knowledge base and search engine.
  • MIX Meta Analysis software for Excel
  • OpenClinica is a web-based platform for managing clinical studies, created by Akaza Research. Key functions include EDC, CRF, protocol, and site management.
  • BioLinux
  • Chiapas is a data translation package that handles mapping, encoding and decoding data between ANSI X12 4010A1 HIPAA data files and a variety of text, file, and database data sources. It works as a C#/.NET project add-in or a standalone clearinghouse.
  • GlassFish ESB Robust open source, light weight integration engine making use of JSR-208 (JBI). Full HL7 V2 and V3 support. Many transport protocols supported including Web Services, HL7 MLLP, TCP/IP, file, batch, etc.
  • Mirth is an open source cross-platform interface engine that enables bi-directional sending of HL7, NCPDP, X12 and DICOM messages between systems and applications over multiple transports. It has data translation capabilities between a large number of formats including database, XML, file, HL7 2.x, and HL7 3.
  • Bots Bots open source EDI translator. Any-to any-translations. Supported data formats: hl7 version 3, edifact, XML, X12, SAP idoc, flat-file, JSON. HL7 version 2 is in development.
  • CommCare an application of JavaROSA to support community health workers to plan their day, manage household visits, and report their data. Jointly developed by many organizations including D-tree International, Dimagi, and theUniversity ofWashington.
  • Epihandy Handheld survey/data collection application
  • The EpiSurveyor Project Handheld survey/data collection application
  • FrontlineSMS enables users to send and receive text messages with large groups of people through mobile phones.
  • Gather AED-Satellife standards-based application for data collection and reporting, with pluggable and interchangeable components/modules for data entry from a full range of wired and mobile computing devices
  • InSTEDD Several unique open-source tools for group-based SMS communication, assisted collaboration, real-time analytics, and mesh synchronization based on mobile technologies
  • JavaROSA open-source J2ME platform for data collection and decision support on mobile devices (used by Episurveyor, Epihandy, GATHER, and CommCare listed below)
  • MobilizeMRS Software that enables health workers to utilize electronic medical records remotely via SMS (using OpenMRS).
  • Mobilisr open source enterprise class mobile messaging platform – used in outreach campaigns for HIV
  • MoCa MoCa is a remote medical diagnostics platform for health workers in developing nations.
  • National Heart and Lung Institute medical software for handhelds
  • RapidSMS RapidSMS is a communications platform for coordinating SMS, voice messages, IVR menus, and email with user and group management – developed by UNICEF
  • Ushahidi Allows people to submit crisis information through text messaging using a mobile phone, email or web form. Displays information in map view.
  • GlassFish ESB Robust open source, light weight integration engine making use of JSR-208 (JBI). Full HL7 V2 and V3 support. Many transport protocols supported including Web Services, HL7 MLLP, TCP/IP, file, batch, etc.
  • Jengine apparently dead integration engine project written in java
  • Mirth is an open source cross-platform HL7 interface engine that enables bi-directional sending of HL7 messages[1] between systems and applications over multiple transports.
  • i2b2 – open source, web services framework designed to provide an integrated, intelligent search engine across many different clinical databases (conceptually termed the ‘Clinical Research Chart’ by the developers). Consists of a server ‘Hive’ (loosely coupled functional/messaging units) and a client interface (Eclipse-based or web-based).
  • OpenGalen computer-based multilingual coding system for medicine
  • [4] NHS Common User Interface (CUI) Programme. This enables a common look and feel across the five regions of the NHS as prescribed within the NHS plan.
  • ODIN Object-oriented Development Interface for NMR (Nuclear Magnetic Resonance)
  • ICD National Center for Health Statistics Classification of Diseases and Functioning&Disabilities
  • LOINC Logical Observation Identifiers Names and Codes – database of codes and universal identifiers for laboratory and other clinical observations
  • The National Drug Code Directory National Drug Code Directory
  • IPath open source telemedicine platform
  • ZephyrOpen Open source SDK for Health Monitoring Devices, like Heart rate monitor
  • IHEOS implementation of IHE (Integrating the Healthcare Environment) actors. IHE defines profiles for the use of various standards in the healthcare environment
  • GELLO – GELLO is the ANSI-accredited standard, HL7 Guideline Expression Language, Object Oriented. Gello.org is an effort to build open source authoring tool for creating GELLO expressions for multiple uses – including decision support, drug prior authorization, matching patients to clinical trials, etc.
  • MARiS Project The MARiS Project goal is to realize a package suite for Radiological Workflow using Open Source tools and technologies in according with IHE guidelines. The architecture of the single packages is based on the concept of IHE actor: this is very useful to develop a system that is an ensemble of single pieces that cooperate together using IHE profiles.
  • Mural Project The Open Source Mural Project from Sun is a robust Master Index. It can be configured as a Master Patient Index, and using the available PIX/PDQ implementation (http://kenai.com/projects/healthcaresolutions), it is IHE Comliant
  • HIEOS HIEOS is an open source implementation of IHE Cross Enterprise Document Sharing (XDS.b) and the Cross Community Access (XCA) integration profiles. The HIEOS platform enables secure health information exchange between various health communities, thereby enabling care providers to have longitudinal perspectives of patients’ health records.
  • The Integrating the Healthcare Enterprise (IHE) has developed a range of open-source interoperability testing tools called MESA, KUDU and its next generation tool GAZELLE to test healthcare interoperability according to the standards profiled by IHE in its technical Frameworks (See below Interoperability testing).
  • Tapeworm Gnome-desktop health profiler to keep track of your diet, including calories and %’s of fat, carbs, and protein, exercise, blood glucose, weight, etc…
  • OpenHRE(tm) Browsersoft Inc. OpenHRE Tool Kit – Proven and scalable platform for establishing Health Information Exchanges and deriving Meaningful Use of collected data. Includes Patient Locater Service/MPI, Record Exchange Service, Authentication and Access Control Service and Business Intelligence capabilities. Used to deploy and demonstrate a Nationwide Health Information Network Prototype. Used to deploy working Health Information Exchanges for State, Metropolitan and Rural intiatives.
  • ActiveHealth Open HIE API – example programs for building industry standard HIE web services interfaces to the ActiveHealth platform clinical intelligence services which include the CareEngine advanced clinical decision support, ActivePHR personal health record/health risk assessment, ActiveAdvice care management desktop, and performance measures.
  • RetroGuide epxress – a tool for EHR data analysis (quality improvement, decision support, research) based on workflow technology.
  • Lamdi Linux Anesthesia Modular Devices Interface
  • Physioneta collection of software for
    • WFDB Software for viewing, analyzing, and creating recordings of physiologic signals
    • record an application for capturing data from an HP CMS (Merlin) monitor
    • apdet Hilbert Transform based Sleep Apnea Detection using a Single Lead Electrocardiogram
    • ecgwave QRS detection and waveform boundary recognition using ecgpuwave
    • edr Derive a respiration signal from one or more ECG signals
    • puka software for detection of breaths in strain gauge recordings
    • many more components available in the Physionet Software Index
  • Medical Algorithms Project Not really software or strictly open source but usable medical algorithms nonetheless
  • HL7 Message browser and radiological image distribution. Last build was in 2003
  • MedMapper Medical decision making algorithm tool. Visual design tool generates Tcl/Tk code. Non-programmers can design interactive algorithms. Generates notes for inclusion in medical record. Runs freestanding or in Tcl Plugin.
  • OS-ELN Web based Electronic Lab Notebook
  • hxp Healthcare Xchange Protocol for interoperative communications. Data exchange/transfer, platform independent, XML-RPC, HL7, SOAP, EDIFACT. Not much activity since 2004.
  • OHF Eclipse foundation Healthcare project to create components to improve interoperability in the healthcare industry
  • Ideopass/ component to manage the identity of the patients in healthcare organizations
  • SQLCare is a clinical database/web application for healthcare providers in the United States
  • EGADSS is an open source tool that is designed to work in conjunction with primary care Electronic Medical Record (EMR) systems to provide patient specific point of care reminders in order to aid physicians provide high quality care
  • 03-MARIS HE compliant Department System IHE Order Filler and PPS Manager, for scheduling and workflow management in radiology department
  • 03-RWS IHE compliant Internationalized Modular Portable Radiology workstation
  • 03-TEBAN allows 3D reconstruction of brain electrical activity from magnetic resonance measurements (MRI) and brain activity mapping even in pathological patients.
  • 03-Fat Brother software for monitoring DICOM and HL7 services
  • 03-XDS is an XDS complete System
  • ROC.KIT This application allows for automated calculation of ROC curves (Receiver-Operating-Characteristic) from continuous medical data like laboratory results.
  • MyDrugRef is a social network of clinicians and pharmacists to improve prescribing. The project is based on Ruby on Rails.
  • Debian-Med largest Linux distribution for free medical software — welcomes requests for packaging based on a solid evaluation.
  • The Integrating the Healthcare Enterprise (IHE) has developed a range of open-source interoperability testing tools called MESA, KUDU and its next generation tool GAZELLE to test healthcare interoperability according to the standards profiled by IHE in its technical Frameworks. These tools are used by commercial and open source implementers. In particular they allow to prepare and perform conformance and interoperability testing at the IHE Connectathons, testing events regularly held around the world each involving over 100 systems.
  • The Certification Commission for Healthcare Information Technology (CCHIT) has developed an open-source program called Laika to test EHR software for compliance with
  • CCHIT interoperability standards.
  1.                          Medical Practice Management Software                         Health System Management
  •                          Imaging/Visualization
  •                          Medical Information Systems
  •                          MPI – Master Patient Index
  •                          Standards Libraries
  •                                   Older Libraries
  •                          Signal Processing
  •                          Research
  •                          Operating System
  •                          Data Translation
  •                          Mobile / Handheld Devices
  •                          Integration
  •                          Coding
  •                          data related to the healthcare industry
  •                          Telemedicine
  •                          IHE
  •                          Private Health Record
  •                          Other
  •                          Out of the box distributions
  •                          Interoperability testing

   See also

Available categories:

There are other similar listings to which I referred to while creating this one. For details please see Further Sources at the end of this page.

Project attributes are listed in the following way:

<project name> [<used license> | <platform> | <client type>] – <project description>

<platform>: Lists all platforms on which the application can be installed and executed. In case of a client-server system that offers web-based access, this represents just the supported platform(s) for the server.

<client type>: Specifies the type of client. “native” means that you have to installed some sort of software on your local workstation to be able to access the application. “web-based” means that you can access the application via a Web browser.

<project description>: A short description of the project. Mostly this is just a copy & paste from the homepage of the project or from the related project page at sourceforge.net.

                   Billing

  • FreeB [GPL | unknown | unknown] – FreeB was the first GPL Medical Billing Engine. FreeB supports the HCFA 1500 and X12 837p 4010a formats. FreeB 2.0 (PHP) is developed by Uversa Inc. and SynSeer. FreeB 1.0 (Perl) is still used by the OpenEMR project. FreeB 1.0 was rewritten as REMITT which is used by the FreeMED project.
  • Cancer Biomedical Informatics Grid™ – The National Cancer Institute (NCI) has launched the caBIG™ initiative to accelerate research discoveries and improve patient outcomes by linking researchers, physicians, and patients throughout the cancer community. The caBIG™ community has developed and released a variety of bioinformatics tools of which an overview is available here. For more details refer to the Open Source Project Site of the National Cancer Institute’s Center for Bioinformatics (NCICB)
  • Caisis [GPL | Windows | web-based] – Caisis is an open-source Web application designed to bridge the gap between clinical research and clinical practice by addressing numerous issues in documentation of patient data. The application was originally designed to track data pertaining to urologic cancer, but now has expanded to track data of other cancers.
    Useful : “The Caisis Project: integrating patient care, research systems and workflows” [2007] by Vora and Fearn.
  • Jumper 2.0 [GPL | multi-platform | web-based] – Bookmarking engine for tagging and linking data objects across remote locations using tag metadata to capture knowledge about data in remote data stores.
  • ·       MIX [GPL | Windows | native] – The MIX program is meta-analysis software for Excel 2000 or later that works like a standalone application. It is thoroughly validated and can be used for educational as well as scientific purposes. (Excel is proprietary software)
  • OpenClinica [LGPL | Linux | web-based] – OpenClinica is a free, open source, web-based electronic data capture (EDC) system for clinical research.
    Useful : “Could an Open-Source Clinical Trial Data-Management System Be What We Have All Been Looking For?” [2008] by Fegan and Lang.
  • ·       Open Infrastructure for Outcomes [GPL | multi-platform | web-based] – OIO is a Web-based medical/patient, user-extensible forms, and online analysis system. It is used at Harbor-UCLA for health/treatment outcomes data. Forms can be exported+imported as XML and exchanged via the online OIO Library at www.TxOutcome.Org. (last news or releases older than a year)
  • phpESP [BSD | multi-platform | web-based] – php Easy Survey Package (phpESP) is a collection of PHP scripts to let non-technical users create surveys, administer surveys, gather results, view statistics. All managed online after database initialization.
  • PyEPL [LGPL | Mac, Linux | native] – PyEPL (Python Experiment-Programming Library) is a library for coding psychology experiments in Python. It supports presentation of both visual and auditory stimuli, and supports both manual (keyboard/joystick) and sound (microphone) input as responses.
  • R Project [GPL | Windows, Mac, Unix | native]– R is a language and environment for statistical computing and graphics.
    • EpiTools [GPL | see above | see above] – Epidemiology tools (epitools) is an R package for epidemiologic computing and graphics.
    • Surveillance [GPL | see above | see above] – The R-package ’surveillance’ is a framework for the development and the evaluation of outbreak detection algorithms in univariate and multivariate routine collected public health surveillance data.
  • SOFA [LGPL/GPL | Windows, Mac, Linux | native] – Simulation Open-Framework Architecture (SOFA) is an Open Source framework primarily targeted at real-time simulation, with an emphasis on medical simulation. It is mostly intended for the research community to help develop newer algorithms, but can also be used as an efficient prototyping tool.

                   Clinical Research

     Useful: “Free and Open Source Enabling Technologies for Patient-Centric, Guideline-Based Clinical Decision Support: A Survey” [2007] by Leong, Kaiser and Miksch.

                   DICOM Tool(kit)

  • Charrua DICOM Toolkit [GPL | multi-platform | native] – DICOM basic constructs used to create the tools at CharruaSoft.com. Its C++ code is a re-interpretation of the original UCDMC library by Mark Oskin. It tries to be much simpler and compact, also uses many Borland VCL specific structures.
  • dcm4che [MPL, GPL, LGPL | multi-platform | web-based] – Open Source Clinical Image and Object Management.

     Useful: “Benefits of Using the DCM4CHE DICOM Archive” [2007] by Warnock et al.

  • DCMTK – DICOM Toolkit [unknown | Windows, Mac, Linux, Solaris | native] – DCMTK is a collection of libraries and applications implementing large parts the DICOM standard.
  • dicom3tools [BSD | Mac, Linux | native] – Command line utilities for creating, modifying, dumping and validating files of DICOM attributes, and conversion of proprietary image formats to DICOM. Can handle older ACR/NEMA format data, and some proprietary versions of that such as SPI.
  • dicom4j [LGPL, GPL | multi-platform | web-based] – Dicom4j is a free and open source Dicom framework for Java. This framework will help to develop DICOM compliant applications. Dicom4j based applications are available from here.
  • dinifti [BSD | Mac, Linux | native] – The dinifti program converts MRI images stored in DICOM format to NIfTI format.
  • DVTk – DICOM Validation Toolkit [LGPL | Windows | native] – The DVTk project creates different tools that will assist in the development, testing and servicing of Medical Interfaces such as DICOM and HL7.

     Useful : “Mastering DICOM with DVTk” [2007] by Potter et al.

  • GDCM (Grassroots DiCoM) [BSD-like license | multi-platform | native] – Gdcm is yet another C++ library dedicated to reading/parsing and writing Dicom medical files.
  • niftilib [public domain | multi-platform | native] – Niftilib is a set of i/o libraries for reading and writing files in the nifti-1 data format. nifti-1 is a binary file format for storing medical image data, e.g. magnetic resonance image (MRI) and functional MRI (fMRI) brain images. Niftilib currently has C, Java, MATLAB, and Python libraries. It is planned to add some MATLAB/mex interfaces to the C library in the future.
  • openDICOM.NET [GPL, LGPL | Windows, Linux | native] – DICOM library, console tools, DICOM viewer/browser for Mono/.NET and Beagle Desktop Search Plugin. The project supports ACR-NEMA and DICOM file formats and provides transcoding to XML. It is written in C#.
  • Utilities for Patient Data Exchange (UPDE) [LGPL | Windows | native] – A parser for text files to use with some of the utilities provided by the DCMTK from Offis. The purpose is to provide a basic DICOM Modality Worklist Management SCP.

Useful: “Evaluation of Open Source DICOM Frameworks” [2006] by Vázquez et al.

                   DICOM Viewer / Server

  • Aeskulap [unknown | Windows, Linux | native] – Aeskulap is a medical image viewer. It is able to load a series of special images stored in the DICOM format for review. Additionally Aeskulap is able to query and fetch DICOM images from archive nodes (also called PACS) over the network.
  • CDMEDIC PACS WEB [ GPL | Linux | native, web-based] – Full featured free PACS based on ctn or dcm4chee, dcmtk and mysql.
  • Conquest DICOM software [unknown | Windows, Linux | native] – Full featured DICOM server based on and heavily extending the public domain UCDMC DICOM code developed by Mark Oskin.
  • ClearCanvas [BSD | Windows | native] – ClearCanvas is a company devoted to creating innovative open source healthcare IT applications. They offer on their homepage a PACS Workstation, a PACS Server, a RIS and a application framework and SDK on which all three applications are based upon. (to download executables registration is required)
  • ImageJ [GPL/LGPL | Windows, Mac, Linux | native, web-based] – ImageJ is a public domain Java image processing program.
  • Java Light PACS Viewer [GPL | multi-platform | native] – jlpv is a Java Light PACS Viewer application useful for review series or images from DICOM data retrieved from the DCM4CHEE PACS system. It also uses ImageJ as a rendering engine or viewer.
  • Kradview [GPLv3 | Linux | native] – Kradview is a GPLed viewer of images obtained for some different sources: X-ray, NMR and DICOM-compatible imaging devices that runs on free operating systems. Its aim is a easy to use DICOM viewer with instant rendering of images, no matter the size and the zoom of the DICOM image. It covers the “let’s see the the X-ray image” need of the medical professional. Kradview as been developed in C and C++ using KDE libraries. The parsing, rendering, and processing routines has been developed in C, and the graphical interface has been developed in C++ and includes the former routines with “extern C” for fast use.
  • OsiriX Imaging Software [GPL | Mac | native] – Open Source PACS Workstation and DICOM Viewer.
  • OpenSourcePACS [LGPL | multi-platform | web-based] – OpenSourcePACS is a free, open source image referral, archiving, routing and viewing system. It adds functionality beyond conventional PACS by integrating wet read functions, implemented through DICOM Presentation State and Structured Reporting standards.
    Useful: “OpenSourcePACS: an extensible infrastructure for medical image management.” [2007] by Bui et al.
  • OSPACS [Cranfield Open-Source License | Windows | native] – Open Source Picture Archiving and Communication System (OSPACS) for storing and displaying medical image files. This is currently been used by the Institute of Women’s Health (University College London) to archive ultrasound images from the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) and aims to store more than 100,000 DICOM files.

     Useful: “OSPACS: Ultrasound image management system” [2008] by Stott et al.

  • PGCTN [GPL | Mac, Linux | web-based] – Pgctn is open source DICOM server/web-based viewing system. It is made by using PHP and javascript. Postgresql (also MySQL), CTN (also DCM4CHEE), DCMTK and other open source software are used for the back end. The feature is to improve using theAJAX.
  • RT_Image [unkown | Windows | native] – A DICOM-compliant 3D image display, analysis, and segmentation package for incorporating molecular imaging data in radiation oncology
  • Stratos viewer [GPL | multi-platform | web-based] – Stratos viewer is a web based utility to examine DICOM medical images through a Web browser.

     Useful: “Open Source in Imaging Informatics” [2007] by Nagy, “Open source software, the future of medical imaging?” [2006] by Henriksen et al.

                   Disaster/Disease Management

  • Real-time Outbreak and Disease Surveillance (RODS) [GPL | multi-platform | web-based] – RODS (Real-time Outbreak and Disease Surveillance) is a real-time computer-based public health surveillance system initially developed at the RODS Laboratory, University of Pittsburgh for the early detection of disease outbreaks.
  • Sahana [LGPL | multi-platform | web-based] – Sahana is a Free and Open Source Disaster Management system. It is a web based collaboration tool that addresses the common coordination problems during a disaster from finding missing people, managing aid, managing volunteers, tracking camps effectively between Government groups, the civil society (NGOs) and the victims themselves.
    Useful : “Sahana Publications, Presentations, and Research”
  • TriSano [AGPLv3 | multi-platform | web-based] – TriSano™ is an open source, citizen-focused surveillance and outbreak management system for infectious disease, environmental hazards, and bioterrorism attacks. It allows local, state and federal entities to track, control and ultimately prevent illness and death.
  • Zyxware Health Monitoring System [GPL | multi-platform | web-based] – ZyxwareHMS is a web based disease monitoring for monitoring diseases like chikungunya, malaria – reported by hospitals in a district, county, state or country. There is a reporting & analysis module and a GIS module which displays the data using google maps.
  • CHITS [GPL, QPL | Windows, Linux | web-based] – The Community Health Information Tracking System (CHITS) is an extensible, modular, open source information system for rural health units (initially for the Philippines). It collects existing routine health data from vertical programs in the Field Health Service Information System (FHSIS) and integrates them into a unified, comprehensive computerized information system.
  • ClearHealth [GPL | unknown | web-based] – ClearHealth is a next generation practice management and EMR. It supports Demographics, Scheduling, Full Medical Billing, Disease Management, Decision Support, EPrescribing, HL7, and Web Services.
  • ·       CottageMed™ [GPL | Windows, Mac, Linux | Filemaker based] – CottageMed™ is a FileMaker Pro application that is flexible, ruggedly dependable and HIPAA-secure Electronic Medical Records system (EMR) … with secure and wireless networking, PDA and multiple-office support, prescription writing and cross-platform. (Filemaker Pro is proprietary software)
  • DHIS 2 [BSD | multi-platform | web-based] – The District Health Information System (DHIS) provides means for data entry, report generation, and analysis. It is part of a larger initiative for health care data in developing countries, called the Health Information System Programme (HISP).
  • FFEHR [GPL | Windows, Linux | web-based] – FFEHR is the temporary project name of a software application commissioned by the ASEAN +3 node of the UNDP’s International Open Source Network (UNDP-IOSN) for eventual use as an electronic health record for the healthcare industry. The initial goal of the project is to be able to design a common user interface that is both effective and efficient, and widely acceptable to medical practitioners in thePhilippines and in the future, worldwide.
  • HOSxP [GPL | Windows | native, web-based] – HOSxP is client/server hospital information system using in 150 hospitals in Thailand. HOSxP has many modules which keep data of Patient Image, Symptoms, Physical Condition, Investigation, Diagnosis, Treatment including Procedure / Medication, etc.
  • IndivoHealth [LGPL | multi-platform | native, web-based] – Indivo is a distributed, web-based, personally controlled health record system that is accessible to the nomadic user and built to public standards. The Indivo project includes a pluggable web services API, web-based UI, data subscription framework, etc.

                   Electronic Medical Record (EMR aka EPR aka EHR)

     Useful: “Indivo: a personally controlled health record for health information exchange and communication” [2007] by Mandl et al.

  • MedClipse [CPL | multi-platform | native] – MedClipse will be an open-source Electronic Medical Record (EMR) software for the swiss general practionner. It will implement things such as agenda, billing (tarmed), medical and administrative data management, prescriptions, referals and other tools.
  • Medical [GPL | Linux | web-based] – Medical is an highly scalable EMR / Hospital Information System (HIS) for OpenERP. It uses industry standards, such WHO ICD-10. The goal is to provide a universal EMR / HIS, where developing countries can also benefit.
  • Med’In Tux [CeCILL | Windows, Mac, Linux | native] – MedinTux is a powerful medical software, multiuser (using MySQL for data storage), easy-to-use (thanks to Qt development toolkit), complete, working from the GP to the hospital. Its unique design makes it the most customisable software you can dream of.
  • MirrorMed [GPL | Linux | web-based] – MirrorMed is a next-generation PHP-based EHR and practice management system.
  • OpenEMR [GPL | Mac, Linux | web-based] – OpenEMR is the complete, user-friendly and affordable electronic medical record system. It is fully compliant with HIPAA and industry standards.
  • OpenMRS [OpenMRS Public License | Windows, Mac, Linux | web-based] – OpenMRS is a community-developed, open-source, enterprise electronic medical record system framework intended to aid resource-constrained healthcare environments.
    Useful : “Cooking Up An Open Source EMR For Developing Countries: OpenMRS – A Recipe For Successful Collaboration” [2006] by Mamlin et al.
  • OpenVista [AGPL | multi-platform | web-based] – OpenVista is a cost-effective, open, trusted and complete EHR which enhances patient safety, increases clinical and operational efficiency and provides an opportunity to improve quality of care delivery.
  • OSCARMcMaster [GPL | multi-platform | web-based] – OSCAR (Open Source Clinical Application and Resource) from McMaster University is a web-based EMR (electronic medical record) system developed for academic primary care clinics yet suitable in specialty and non-teaching practices.
  • PatientOS [GPL | multi-platform | native] – PatientOS has been designed from the outset to be a Healthcare Information System (HIS). The software architecture, design patterns and framework has been built for the complexities and challenges of an enterprise wide information system.
  • Tolven Health Record [LGPL | multi-platform | web-based] – The Tolven platform and ePHR and eCHR applications enable interoperability across electronic health records for consumers and clinicians. Using Java 5, EJB3, Faces, Facelets,AJAX, relational database, and LDAP for security.
  • Ultimate EMR [GPL | Windows, Linux | web-based] – A feature rich Open Source Core Electronic Medical Record for small medical providers developed with Plone/ Python/ Zope. Core EMR functionalities: Patient History, Past Visits, Rx, Health Maint., Allergies, Labs, Vitals, Notes, and Procedures.
  • WorldVistA [GPL | Linux, Windows | native] – WorldVistA EHR is based on the highly acclaimed VistA system of the United States Department of Veterans Affairs (VA).

     Useful: “Open-Source EHR Systems for Ambulatory Care: A Market Assessment” [2008] by the California HealthCare Foundation.

                   HL7 Tool(kit)

  • HAPI [GPL, MGPL | multi-platform | native] – HAPI (HL7 application programming interface; pronounced “happy”) is a Java-based HL7 2.x parser with support for traditional (ER7) and XML encoding.
  • HL7v3 Test Harness [GPL | Windows | native] – The HL7 Test Harness system is an HL7 v3 message conformance testing application that also provides the ability to simulate the message processing actions of a client and/or server system. The application provides message workflow, format and content testing.
  • NHapi [MPL | multi-platform | native] – .Net version of HAPI Object oriented HL7 2.X parser. HL7 parser/encoder written in Microsoft .Net C#. Can encode/decode both XML and Pipe Delmimited formats.
  • Perl HL7 Toolkit [GPL | multi-platform | native, web-based] – The HL7 toolkit provides a lightweight Perl API for manipulating, sending and receiving HL7 messages, an implementation of a forking HL7 server and an HL7 queue daemon.
  • QuickViewHL7 [AFL | Windows | native] – HL7 file viewer, in tree-view format, with associated segment/field documentation. Basic usage is for testing and bug-tracing HL7 communications applications. Needs .Net Framework 2.0 to run.
  • Ruby HL7 [BSD license | multi-platform | web-based] – Ruby HL7 is a simple library for parsing and generating HL7 2.x messages. 3.x support is planned in the future.
  • OpenRep FREE [GPL | multi-platform | native] – OpenRep is a Java desktop application designed to serve as a homeopathic software with capabilities to open and use multiple repertories, perform repertorizations and view its results, manage patients and view different materia medicae. It is also designed to save and load data in human readable xml format.
  • CARE2X [GPL | Windows, Mac, Linux | web-based] – Care2x integrates data, functions and workflows in a healthcare environment (Hospital/Healthservice Information System, Practice management, Central Data Server, Health Xchange Protocol).
  • Hospital OS [GPL | Windows, Linux | native] – Hospital OS is a hospital information system for small-sized hospitals (100 beds or less, 200 out-patients per day or less). Hospital OS was developed for the healthcare system ofThailand targeting its small community hospitals nation-wide.
  • Mediboard [GPL | multi-platform | web-based] – Mediboard is a web based open source system to manage Healthcare structures. The system is based on a web multi-layers architecture to manage various interconnected modules, using PHP, XML, XHTML, Javascript, CSS, Smarty and PEAR.
  • Open Hospital [GPL | multi-platform | unkown] – Open Hospital – Hospital Information System for Angal – Uganda. Patient management, pharmacy, laboratotry, pregnancy and malnutrition control management. Developed by Informatici Senza Frontiere.
  • OpenMEDIS [GPL | multi-platform | web-based] – OpenMEDIS is a simple, flexible, and standardized tool to collect (inventory) and process (manage) information on health technology infrastructure, e.g. medical devices in low- and middle income countries.
  • TurnHos [GPL | multi-platform | web-based] – TurnHos is based on the system Care2x, integrates data, functions and workflow in an environment of health care, in addition to the administration schedule, print appointments and admission of patients.
  • Bots [GPL | multi-platform | native] – Bots for the translations and communication needed in Electronic Data Interchange (EDI). Bots has three main functions: “Any-to-any-format” data conversions, (Secure) communications and manage and overview EDI data flows.
  • Chiapas [project specific license | Windows | native] – Chiapas is an enterprise level HIPAA data translation package. It supports all major healthcare transactions and a variety of SQL databases and file types, and incorporates a script parser and a GUI studio for development and maintaining specifications.
  • Dataserver [LGPL | multi-platform | native, web-based] – DataServer is an open source XML gateway, specially tailored for the medical domain. DataServer is middleware, situated between clients and traditional Health Information Systems (HIS), Radiology Information Systems (RIS) and Picture Archive and Communication Systems (PACS). It supports relational (SQL), SOAP, and HTTP data sources out of the box, but is highly extensible for custom types.
  • Laika [Apache License | Windows, Linux | unkown] – Laika analyzes and reports on the interoperability capabilities of EHR systems. This includes the testing for certification of EHR software products and networks.
  • Mergence [GPL | multi-platform | native] – Mergence is a high performance, open source HL7 integration engine and application platform.
  • mirth [MPL | unknown | web-based] – Mirth is an open source cross-platform HL7 interface engine that enables bi-directional sending of HL7 messages between systems and applications over multiple transports.
  • Bika LIMS [GPL | multi-platform | web-based] – Bika combines web content management and workflow processing for a one-stop web-based Laboratory Information Management System.
  • OpenELIS [UIRF Open Source Based Public Software License | multi-platform | web-based] – OpenELIS is a robust Enterprise Laboratory Information System built around an extensible and scalable framework. OpenELIS is designed and developed through the collaborative efforts of Public Health Laboratories to accommodate business processes that are common to all public health laboratories; encompassing clinical, environmental, newborn screening, and animal testing. The goal of the OpenELIS team is to develop a state of the art system that is economically sustainable by reducing both initial investment and ongoing maintenance costs.
  • YaNuCa [GPL | multi-platform | web-based] – YaNuCa (Yet Another Nutrition Calculator) is a web-based calculator for enteral and parenteral nutrition in adult intensive care patients. YaNuCa is a JavaScript program using a compact xHTML form as front end, which can easily be used with any JavaScript 1.2+ capable graphical web browser.
  • eleMental Clinic [GPL | Mac, Linux | web-based] – eleMental Clinic is an Open Source medical records management system for mental health professionals.
  • Elexis Praxisprogramm [EPL | multi-platform | native] – An Eclipse RCP program for all aspects of a medical practice: EMR, laboratory findings etc., as well as accounting, billing (Swiss TARMED-System, other systems to be developped) and other daily work.
  • FreeMED [LGPL | Linux | web-based] – Electronic Medical Record and Practice Management system for medical providers that runs in any Web browser in multiple languages. It provides an XML-RPC backend and multiple import and export formats, as well as reporting and other features.
  • Freemed-YiRC [GPL | Linux | web-based] – Freemed-YiRC is a software project which aims to provide a product capable of providing Child Caring agencies/Youth in Residential Care (YiRC) agencies/Foster Care agencies with a fully functional internal case management/information system.
  • GNUmed [GPL | Windows, Mac, Linux | native] – GNUmed is a medical practice management software
  • OpenTAPAS [GPL | multi-platform | native] – Technology Assisted Practice Application Suite (TAPAS) is a term that describes digital tools that assist physicians deliver care in a paper based office. OpenTAPAS builds upon the HL7 compliant Electronic Medical Summary Standard.
  • Res Medicinae [GPL | multi-platform | web-based] – Res Medicinae is the attempt to overcome high pricing in the realm of medical information systems and to provide users with a stable, platform independent, extensive system using latest technology and being open to many other medical systems.
  • SQL Clinic [unknown | multi-platform | web-based] – SQL Clinic is a clinical database/web application for psychiatric providers in the United States. It is written in perl and runs on the GNU/Linux, FreeBSD, Mac OS X and Win32 platforms. It supports three databases: Postgres, MySQL and Oracle (probably inactive, last news/releases 03/2006).
  • MARiS [GPL | multi-platform | web-base] – The MARiS Project goal is to realize a package suite for Radiological Workflow using Open Source tools and technologies in according with IHE guidelines. The architecture of the single packages is based on the concept of IHE actor: this is very useful to develope a system that is an ensamble of single pieces that cooperate together using IHE profiles.
  • BioSig [GPL | multi-platform | native] – BIOSIG is an open source software library for biomedical signal processing. Library works well with Octave and Matlab. Special emphasis is put on EEG/MEG/ECoG, but also other types of biosignals like ECG, EMG, etc. are supported.
  • FSL [FMRIB | Windows, Mac, Linux | native] – FMRIB Software Library (FSL) is a comprehensive library of analysis tools for FMRI, MRI and DTI brain imaging data. FSL is written mainly by members of the Analysis Group, FMRIB, Oxford, UK. FSL runs on Apple and PCs (Linux and Windows), and is very easy to install. Most of the tools can be run both from the command line and as GUIs (”point-and-click” graphical user interfaces).
                   Hospital Management
                   Integration Tool(kit) / Middleware
                   Laboratory
                   Practice Management
                   Radiology
                   Signal Processing
     Part of FSL is FSLView, a viewer for (f)MRI and DTI data.
  • Octave [GPL | multi-platform | native] – GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with Matlab. It may also be used as a batch-oriented language.
  • Lipsia [GPL | Linux | native] – Leipzig Image Processing and Statistical Inference Algorithms (Lipsia) is a software tool for processing functional magnetic resonance imaging (fMRI) data. It was developed over the course of several years at the Max-Planck-Institute for Human Cognitive and Brain Sciences inLeipzig,Germany.
  • ODIN [GPL | multi-platform | native] – ODIN is a free software framework for rapid prototyping of magnetic resonance imaging (MRI) sequences. The sequences can be tested, simulated and executed on scanner hardware from different manufacturers.
  • PyMVPA [MIT | multi-platform | native] – PyMVPA is a Python module intended to ease pattern classification analyses of large datasets. In the neuroimaging contexts such analysis techniques are also known as decoding or MVPA analysis. PyMVPA provides high-level abstraction of typical processing steps and a number of implementations of some popular algorithms. While it is not limited to the neuroimaging domain, it is eminently suited for such datasets. PyMVPA is truly free software (in every respect) and additionally requires nothing but free-software to run.
  • IPath [GPL | multi-platform | web-based] – iPath is providing a free and open platform for many kind of telemedical applications. iPath-Server, provides a sort of medical BBS to discuss/consult online. Additional modules can be added, e.g. iPath-Microscope for real time telemicroscopy.
  • Xebra [GPL | multi-platform | web-based] – Xebra is an open source platform for web-based distribution and clinical review of medical imaging results. Xebra is based on the latest open industry standards including JPEG2000, WADO and IHE XDS-I. The software provides healthcare organizations and software developers with all the necessary components to securely transmit and review medical images over a network such as the Internet.

                                                                  Telemedicine

.

                   Visualization

  • 3D Slicer [BSD-like license | Windows, Mac, Linux | native] – The 3D Slicer uniquely integrates several facets of image-guided medicine into a single environment. It provides capabilities for automatic registration (aligning data sets), semi-automatic segmentation (extracting structures such as vessels and tumors from the data), generation of 3D surface models (for viewing the segmented structures), 3D visualization, and quantitative analysis (measuring distances, angles, surface areas, and volumes) of various medical scans.
  • AMIDE [GPL | Windows, Mac, Linux | native] – Amide (Amide’s a Medical Image Data Examiner) is a tool for viewing, registering, and analyzing anatomical and functional volumetric medical imaging data sets. It imports most clinical DICOM files (using the DCMTK library).
  • BioImageXD [GPL | Windows, Mac, Linux | native] – BioImageXD is a free open source software for analysis, processing and 3D rendering of multi dimensional, multi data channel, time series image data from microscopy and other sources.
  • ·       BrainStorm [GPL | Matlab | native] BrainStorm is an integrated free Matlab toolkit dedicated to Magnetoencephalography (MEG) and Electroencephalography (EEG) data visualization and processing. Our intention is to make a comprehensive set of tools available to the scientific community involved in MEG/EEG experimental research. (Matlab is proprietary software)
  • ·       BrainVISA [CeCILL license, GPL | Windows, Mac, Linux | native] – BrainVISA is a software, which embodies an image processing factory. It is distributed with a toolbox of building blocks dedicated to the segmentation of T1-weighted MR images. (last news or releases older than a year)
  • CTSim [GPL | Windows, Linux | native] – CTSim simulates the process of transmitting X-rays through phantom objects. These X-ray data are called projections. CTSim reconstructs the original phantom image from the projections using a variety of algorithms. Additionally, CTSim has a wide array of image analysis and image processing functions.
  • DeVIDE [BSD | Windows, Linux | native] – DeVIDE, or the Delft Visualisation and Image processing Development Environment, is a cross-platform software framework for the rapid prototyping, testing and deployment of visualisation and image processing algorithms. The software was developed within the Visualisation group. DeVIDE’s primary (and currently only) front-end is a data-flow boxes-and-lines network editor. In this regard, it is very similar to AVS, OpenDX, Khoros or VISSION. DeVIDE integrates functionality from libraries such as VTK, ITK, GDCM, DCMTK, numpy and matplotlib. It is being very actively developed.
  • Drishti [GPL | Windows, Mac, Linux | native] – Drishti (meaning “vision” or “insight” in Sanskrit) is a multi-platform, open-source Volume Exploration and Presentation Tool. It was written for visualizing tomography data, electron-microscopy data and so forth.
  • Endrov [BSD license | multi-platform | native] – Endrov is an open-source plugin architecture aimed for image analysis and data processing.
  • Gwyddion [GPL | Windows, Mac, Linux | native] – Gwyddion is a modular program for SPM (scanning probe microscopy) data visualization and analysis. Primarily it is intended for analysis of height fields obtained by means of scanning probe microscopy techniques (AFM, MFM, STM, SNOM/NSOM), however it can be generally used for any other height field and image analysis.
  • ITK [BSD-like license | multi-platform | native] – ITK is an open-source software toolkit for performing registration and segmentation.
  • ITK-SNAP [unknown | Windows, Mac, Linux | native] – ITK-SNAP is a tool for segmenting anatomical structures in medical images. It provides an automatic active contour segmentation pipeline, along with supporting manual segmentation toolbox. ITK-SNAP has a full-featured UI aimed at clinical researchers.
  • MITK [BSD-like license | multi-platform | native] – The Medical Imaging Interaction Toolkit (MITK) is a free open-source software system for development of interactive medical image processing software. MITK combines the Insight Toolkit (ITK) and the Visualization Toolkit (VTK) with PIC-based libraries of the DKFZ. As a toolkit, MITK offers those features that are relevant for the development of interactive medical imaging software covered neither by ITK nor VTK.
  • Ogles [GPL | multi-platform | native] – Ogles is slice data visualization tool based on OpenGL. Ogles started out as a planning system for frame based stereotactic neurosurgery. Current development targets at a framework for neuroanalysis. A simple DICOM reader (SDR) is part of the project.
  • OpenMS [LGPL | Windows, Mac, Linux | native] – An open source framework for LC-MS based proteomics. OpenMS offers datastructures and algorithms for the processing of mass spectrometry data. The library is written in C++.

     Useful: “OpenMS – An open-source software framework for mass spectrometry” [2008] by Sturm et al.

  • ParaView [BSD-like license | Windows, Mac, Linux | native] – ParaView is an open source, freely available program for parallel, interactive, scientific visualization.
  • TEMPO [GPL | multi-platform | native] – TEMPO (Topographic Eeg Mapping PrOgram) is open source software for 3D visualization of brain electrical activity. TEMPO accepts EEG file in standard EDF format and creates animated sequence of topographic maps.
  • VTK [BSD-like license | multi-platform | native] – The Visualization ToolKit (VTK) is an open source, freely available software system for 3D computer graphics, image processing, and visualization.
  • Voreen [GPL | Windows, Mac, Linux | native] – The goal of the Voreen project is to develop an open source volume rendering engine which allows interactive visualization of volumetric data sets by allowing high flexibility when integrating new visualization techniques.
  • (X)MedCon [LGPL | Windows, Mac, Linux | native] – XMedCon is a medical image conversion utility and library; hereby hoping to lower at least one barrier in medical research projects. The supported formats are: Acr/Nema 2.0, Analyze (SPM), Concorde/µPET, DICOM 3.0, CTI ECAT 6/7, NIfTI-1, InterFile3.3 and PNG or Gif87a/89a.
  • Debian-Med [various | Linux | non-applicable] – Debian-Med is a “Custom Debian Distribution” with the aim to develop Debian into an operating system that is particularly well fit for the requirements for medical practice and research. The goal of Debian-Med is a complete system for all tasks in medical care which is built completely on free software. Talks and further info about Debian-Med can be found here. There is also a Wiki available.
  • EGADSS Decision Support System – Evidence-based Guideline and Decision Support System. Provides patient specific point of care reminders in order to aid physicians provide high quality care. Input/output in the form of HL7 CDA Level 2 documents. Knowledge is encoded using Arden Syntax.
  • iHRIS Software Suite [GPL | Windows, Linux | web-based] – The Capacity Project is developing three free and Open Source core software solutions, each addressing a specific human resources for health (HRH) leadership issue. iHRIS Qualify: a training and licensure tracking database for Linux servers. iHRIS Manage: a human resources management system for Linux servers. iHRIS Plan: workforce planning and modeling software for Linux servers. Offline iHRIS: Windows desktop version of all three components of the iHRIS Suite.
  • Linux For Clinics [GPL | Linux | non-applicable] – The Goal of Linux For Clinics is to create a free medically-themed linux distribution combining the work of Debian-Med with the release schedule and support of Ubuntu. They also have a Blog.
  • Open eHealth Foundation – Agfa HealthCare, InterComponentWare (ICW), and Sun Microsystems Inc. have joined as foundation members the new Open eHealth Foundation. The Open eHealth Foundation will provide software components under an Open Source license that will boost the open standards-based exchange of medical information.
  • OpenEMPI – OpenEMPI seeks to provide an open community towards development and critical evaluation of open source solutions for use as a community or enterprise master patient index (”MPI”).
  • Open Healthcare Framework – The Eclipse Open Healthcare Framework (OHF) is a project within Eclipse formed for the purpose of expediting healthcare informatics technology. The project is composed of extensible frameworks and tools which emphasize the use of existing and emerging standards in order to encourage interoperable open source infrastructure, thereby lowering integration barriers.
  • Open Health Tools – Open Health Tools is an open source community with a vision of enabling a ubiquitous ecosystem where members of the Health and IT professions can collaborate to build interoperable systems that enable patients and their care providers to have access to vital and reliable medical information at the time and place it is needed.
  • OpenMedSpel [GPL | multi-platform | native] – OpenMedSpel is a free and open source USA English medical spelling word list.
  • CEN Technical Committee 251 – Health Informatics – CEN/TC 251 is the body within Europe mandated to develop standards for Health Informatics. (Useful: EN13606-1 documents)
  • DICOM – Digital Imaging and Communications in Medicine. (Useful: DICOM 3 standard definition of 2007)
  • Foundational Model of Anatomy – The Foundational Model of Anatomy Ontology (FMA) is an evolving computer-based knowledge source for biomedical informatics; it is concerned with the representation of classes or types and relationships necessary for the symbolic representation of the phenotypic structure of the human body in a form that is understandable to humans and is also navigable, parseable and interpretable by machine-based systems. Specifically, the FMA is a domain ontology that represents a coherent body of explicit declarative knowledge about human anatomy. Its ontological framework can be applied and extended to all other species. It can be browsed via the Foundational Model Explorer.
  • HL7 – Framework and related standards for the exchange, integration, sharing and retrieval of electronic health information.
  • HXP – HXP is a standard data exchange protocol that could be used by healthcare applications to communicate transparently with each other regardless of their platforms. It is a protocol for making and receiving procedure calls over the internet and thus allow reception and transmission of data among remote healthcare applications.
  • IHE – IHE is an initiative by healthcare professionals and industry to improve the way computer systems in healthcare share information. IHE promotes the coordinates use of established standards such as DICOM and HL7 to address specific clinical need in support of optimal patient care. Systems developed in accordance with IHE communicate with one another better, are easier to implement, and enable care providers to use information more effectively.

                   Other

                   Standards

     Useful: IHE Technical Frameworks and Integration Profiles

                   Further Sources

Document Downloads

Open-Source EHR Systems for Ambulatory Care: A Market Assessment (529K)

Appendix A to Open-Source EHR Summary: Research Methodology (20K)

Appendix B to Open-Source EHR Summary: General Concepts (674K)

Appendix C to Open-Source EHR Summary: Systems Reviewed in Detail (682K)

Appendix D to Open-Source EHR Summary: Other Noteworthy Systems (39K)

Appendix E to Open-Source EHR Summary: Benefits and Limitations of FOSS EHRs (32K)

Appendix F to Open-Source EHR Summary: Additional FOSS EHR Resources (17K)

Leveraging Investments and Sharing Knowledge

Understanding TUBERCULOSIS

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                                                                                                         TUBERCULOSIS:

The present  global situation

Tuberculosis (TB) has been curable for more than 50 years, yet it continues to cause an immense burden of morbidity and mortality. Approximately one-third of the world’s population is infected with Mycobacterium tuberculosis, with 8 to 10 million developing active TB and ~3 million dying of TB each year (almost half of whom are co-infected with HIV). About 95% of cases occur in low-income countries and 75% are in the 15-50 age group. Both globally and within countries, there is a striking link between poverty and TB.

Two important developments have occurred in the past two decades:

  • TB incidence has increased dramatically in communities highly endemic for HIV.
  • The emergence of drug resistance jeopardizes both individual treatment and control of the disease in communities. In 1993, WHO declared TB a global emergency?
    Map of the 22 HBCs (high-burden countries) tha...

    Modern TB treatment regimens of 6 to 9 months are highly effective in curing patients and preventing transmission. TB treatment is among the most cost effective of all health interventions. In recent years TB has been recognized as a health and development priority with substantial expansion of TB control programmes.Many years of experience, including both disastrous failures and gratifying successes, has led to the recognition of several basic principles of TB treatment and control:TB treatment and control is first and foremost a public health activity since identifying and curing infectious patients is the most important element in reducing transmission in the community.In every setting, TB patients are more likely to be poor and disadvantaged, with more difficulties accessing health care.Thus it is vital that the public sector take responsibility for ensuring the proper functioning of the programme, usually through the establishment of a National Tuberculosis Programme, and that treatment be provided free of charge to patients.Many of the functions of successful TB treatment and control (see box) can only be provided effectively through a well-organized programme structure, usually operating nationwide.Finally, the TB programme must be integrated with the general health services of the community since that is where TB cases present. Elements of the WHO TB control strategySustained political commitmentMicroscopy: case detection among symptomatic patients attending health services using sputum smear microscopySCC/DOT: standardized short-course chemotherapy (SCC) using regimens of 6-8 months for at least all confirmed smear-positive cases. Good case management includes directly observed therapy (DOT) during the intensive phase for all new sputum-positive cases, during the continuation phase of regimens containing rifampicin, and throughout a re-treatment regimen.Drug supply: establishment and maintenance of a system to supply all essential anti-TB drugs, and to ensure no interruption in their availability.Recording and reporting: establishment and maintenance of a standardized recording and reporting system, allowing assessment of treatment results. MicrobiologyMycobacteria are slender, curved, aerobic bacilli whose cell wall components make them acid-fast on Ziehl Neelsen (ZN) staining. Members of the genus Mycobacterium are listed in the box.M. tuberculosis multiplies slowly so that up to 6 weeks are required for culture. Correspondingly, disease due to M. tuberculosis tends to progress slowly, and responds slowly to treatment in comparison with infections due to common pyogenic bacteria. Transmission M. tuberculosis is acquired by the inhalation of microscopic droplets produced by individuals with active pulmonary TB, during coughing, sneezing, or speaking. Overcrowded, poorly ventilated conditions increase the risk of transmission as does duration of exposure. Other sources of M. tuberculosis infection, except for handling TB cultures in the laboratory, are extremely rare.M. bovis is a pathogen in cattle and can infect a wide range of domestic and wild animals. As with M. tuberculosis, it is primarily transmitted by droplet inhalation, but human infection can occur through ingestion of unpasteurized milk from infected cows. Disease and pathogenesis ZN stain for Myc TB( from Wikipedia)

     

     

     

     


     

     

     

     

     TB infection

     

     Aerosolized droplets containing M. tuberculosis enter alveoli and initiate a non-specific response. The bacilli are ingested by macrophages and transported to regional lymph nodes. They may either be contained there or spread via the lymphatics or bloodstream to other organs.

    With the development of cell-mediated immunity, cytokines secreted by lymphocytes recruit and activate macrophages, which organize into the granulomas characteristic of TB, surrounded by lymphocytes, effectively walling in the organisms.

    In an immunocompetent host, most granulomas heal. They can sometimes be seen on CXR; more commonly the lesion is not detectable radiographically and a positive tuberculin skin test (TST) is the only evidence of infection.

    Although the lesions become fibrotic, bacilli can persist intracellular in macrophages in a quiescent state capable of reactivation at a later time. This is known as  latent tuberculous infection.

    Active TB disease

     On average ~10% of adults infected with M. tuberculosis ultimately develop active TB, with about half of this risk occurring in the first 1-2 years after infection and the other half distributed over the remainder of the individual’s lifetime. A number of factors can substantially increase the risk of disease reactivation

    In a minority of cases, particularly infants or those with depressed cell-mediated immunity, 1° infection is not contained and symptomatic or disseminated disease (progressive 1° TB) develops directly from 1° infection.

    Post-primary TB

     Occurs as a reactivation of latent infection, often years or even decades after the 1° infection. The genus Mycobacterium includes

    • M. tuberculosis complex (M. tuberculosis, M. bovis, M. bovis BCG, M. africanum): very closely related organisms of which M. tuberculosis is the most important human pathogen.
    • M. leprae, the cause of leprosy, is an important mycobacterial pathogen of humans.
    • Mycobacteria other than TB: mainly environmental organisms which cause a spectrum of relatively uncommon human diseases (e.g. M. avium complex, M. kansasii, M. fortuitum, M. marinum.) M. ulcerans is the cause of Buruli ulcer, a destructive cutaneous mycobacteriosis seen with increasing frequency inWest Africa. Person to person transmission has not been observed with these organisms. This group will not be considered further in this chapter.
      Main symptoms of different variants and stages...

      Risk factors for development of active TB disease in individuals infected with M. tuberculosisHIV - the most powerful known factorRecent infection - the risk/year of developing active disease is much greater in the first 1–2 years after infectionAge - weakened immunity at the extremes of ageMalnutrition, including vitamin D deficiencyDiabetes mellitusSilicosisIntercurrent infections (eg. measles, visceral leishmaniasis)Toxic factors (eg. alcohol and smoking)Poverty -probably many biologic mechanisms involvedImmune suppression (e.g. corticosteroid therapy, malignancy)Herd immunity- members of populations with little historical exposure to TB appear to be more susceptible to disease.Clinical featuresMany settings where TB care is provided will not have access to some of the high technology diagnostic equipment mentioned below, which may be required for the diagnosis of less common forms of TB. However, most cases of TB can be diagnosed with very basic resources, in particular smear microscopy.Primary TB: symptomatic primary TB is mainly a disease of children. It may be suspected clinically in the presence of fever, malaise, and cough, particularly in the setting of recent TB exposure. The diagnosis may be assisted by documenting TST conversion or supported by a positive TST in a patient likely to have been negative previously. A positive smear or even culture is uncommon. A CXR may show enlarged hilar or paratracheal lymph nodes with or without lung consolidation. A diagnosis of symptomatic primary TB is an indication for anti-TB therapy. Post-primary or reactivation TB:One or more non-specific systemic symptoms are usually present including weight loss, anorexia, fever, night sweats, or malaise.In adults, pulmonary TB (PTB) is the most common presentation. It is also the most important type of TB epidemiologically since it accounts for most transmission. However, TB may affect any organ in the body resulting in organ-specific symptoms and signs. Extrapulmonary TB is more common in children and in HIV-infected patients.Pulmonary TB (PTB): involves the lung parenchyma. A history of cough is present in most cases. A cough of long duration is unlikely to be due to common respiratory infections, hence cough lasting >2 to 3 weeks is an indication for sputum smear microscopy. The cough may be productive but often is not. Haemoptysis, chest pain, breathlessness may also be present in some patients.Examination is often normal or the findings non-specific. Some patients may look ill and wasted with a fever and tachycardia, but some patients, even with infectious TB, appear surprisingly well. Chest examination may reveal localized crackles or a pleural effusion. Finger clubbing indicates that a diagnosis other than TB is likely, but prolonged PTB or lung damage from past PTB can cause bronchiectasis and clubbing.Approximately 65% of PTB cases are sputum smear positive. Sputum smear positivity is more likely in patients who are (a) most infectious (smear-positive patients are several times more likely to transmit TB than are those who are smear-negative, even if culture positive) and (b) sickest.A positive smear for acid-fast bacilli in a high TB prevalence area almost always indicates TB.Smear-negative pulmonary TB:Smear-negative PTB is common but difficult to diagnose accurately. Underdiagnosis is clearly undesirable since an opportunity for effective treatment is missed. Over diagnosis also creates problems, using scarce resources from a very important health programme, overlooking other treatable diagnoses, and undermining the TB programme's credibility in the community. Monitoring the proportion of smear-negative vs. smear-positive pulmonary patients in a programme is a useful indicator of any tendency to over diagnosis of TB. Roughly, the expected proportion of smear-positive: smear-negative is 2:1.Pleural TB: An effusion can often be detected on physical examination and confirmed by X-ray or by diagnostic aspiration with a small gauge needle. In high TB endemic areas, and in the absence of obvious alternative explanations such as heart failure, acute pneumonia, or disseminated KS, TB will be the most common cause of a straw-colored effusion. TB effusions are exudates (fluid protein > half that in serum) and the stained smear contains increased lymphocytes but is seldom positive for acid-fast bacilli. Culture of pleural biopsy tissue is very sensitive and histology of the biopsy usually shows granulomas. Complications of pulmonary TB: Haemoptysis can be life-threatening. Pneumothorax can occur. Dissemination to other organs can occur before treatment is started. Chronic complications include post-TB bronchiectasis, extensive lung fibrosis, and aspergillums (fungus balls) in persistent cavities.TB lymphadenitis: can involve any site, most frequently cervical lymph nodes. Nodes may initially be rubbery and non-tender, becoming matted or fluctuant (cold abscess), sometimes progressing to the development of chronic draining sinuses. They may have been present for weeks or months, and are seldom acutely inflamed. Sometimes TB lymph nodes enlarge or discharge during anti-TB therapy. These characteristics, and the asymmetrical involvement, help to distinguish TB adenitis from persistent generalized lymphadenopathy of HIV.Often a needle aspiration will find a pocket of pus in the node, and this may be smear-positive in some cases (especially if HIV infected). Definitive diagnosis is by surgical biopsy with histologic examination and/or culture where available.Bone TB:Most commonly affects the spine (Pott's disease). Vertebral collapse may ultimately produce a characteristic angular deformity. Some patients develop features of spinal cord compression. Paravertebral cold abscesses or psoas abscesses may accompany Pott's disease and may be relieved by needle drainage they do not generally require open surgical drainage. The presence of a characteristic kyphosis in a TB-endemic area is virtually diagnostic of spinal TB.X-ray changes with intervertebral disc and adjacent bony involvement +/- paravertebral soft tissue densities are characteristic but do not distinguish between TB and other infections such as brucellosis. A cold abscess when present can be aspirated for culture. Imaging-guided biopsy requires sophisticated resources. Spinal TB responds well to drug treatment.Patients with severe deformities or with progressive neurologic compromise might benefit from neurosurgical stabilization if available, but neurologic improvement often occurs with medical therapy alone. TB of other joints such as hip and knee generally require biopsy for diagnosis and respond well to chemotherapy.CXR

       

       

       

       

       

       

       

       

       

       

       

       

      Miliary TB:

       

      Most commonly affects infants and the immunosuppressed. There is a history of gradual onset fever, malaise, and weight loss in the absence of other apparent causes. Clinical suspicion is raised in a child with known or likely recent contact with an infectious TB patient. Physical findings are commonly non-specific, but include hepatomegaly, slight splenomegaly, tachypnoea, and neck stiffness (meningitis may complicate military TB). Progression to death occurs in the absence of therapy.

      Chest X-ray characteristically shows diffuse, tiny, nodular opacities. Sputum smear examination and TST are often negative; where available, biopsy of liver, bone marrow, lymph nodes, or lung parenchyma may yield acid-fast bacilli or granulomas.

      TB meningitis

      Most commonly seen in children and the immunosuppressed. Clinical presentation includes headache, irritability, vomiting, decreased consciousness, or any unexplained progressive central neurologic syndrome. The history is usually less acute than in bacterial meningitis. Neck stiffness may be mild at first, later opisthotonus; coma may occur. Cranial nerve palsies (III, IV, VI, and VIII particularly) occur, reflecting basilar distribution of the disease. Seizures and focal neurologic deficits may also occur.

      Diagnosis rests on CSF examination.

      There is typically a lymphocytosis with raised protein and decreased glucose in early disease, mild changes may be present. CSF should also be examined for cryptococcus if there is a possibility of HIV infection. Unless concentrated the CSF is rarely positive for acid-fast bacilli; cultures may become positive in most cases.

      Once a diagnosis has been made on the basis of clinical features, suggestive CSF abnormalities, and the absence of a likely alternative diagnosis, TB treatment should be started immediately.

      The available evidence and most expert opinion support adjunctive therapy with corticosteroids.

        Abdominal TB:

       

       Gastrointestinal TB may present as partial bowel obstruction with a history of fever. It can occur at any site in the GI tract, most commonly the terminal ileum. The diagnosis is likely to be made at surgery or endoscopy. Granulomatous hepatitis is characterized by a systemic illness with laboratory evidence of cholestasis and diagnosed on liver biopsy. Peritoneal TB may be suspected on the basis of ascites without another obvious cause such as liver disease and portal hypertension the ascites has the same characteristics as TB pleural fluid (see above). The peritoneum has a characteristic appearance on direct inspection; peritoneal biopsy, ideally taken at laparoscopy, with culture and histology provides a definitive diagnosis.

      Pericardial TB:

      Often first suspected on the basis of globular enlargement of the cardiac silhouette on CXR in patients being investigated for a variety of systemic and cardio respiratory symptoms. It is seen more frequently in HIV-infected patients. A pericardial rub or clinical features of tamponade (elevated jugular venous pressure, pulsus paradoxus, hypotension) may be present. Ultrasound readily confirms the presence of an effusion. Pericardial fluid has the same characteristics as pleural fluid (see above). The risk of tamponade acutely, and constriction later on, may be reduced by adding corticosteroids for the first 6-12weeks of TB treatment.

      Genitourinary TB:

      Can involve any part of the male or female genitourinary tract. Presentation is sub acute and diagnosis usually requires TB culture or histology of biopsies. Renal TB presents with dysuria, hematuria, flank pain, or mass. The urine contains pus cells on microscopy, but is negative on culture for common bacteria. Genital tract TB in women presents as infertility, pelvic pain, mass, or abnormal bleeding. Epididymal swelling is the most common presentation of genital TB in males.

      TB in children

      The risk of progression to disease following M. tuberculosis exposure is greater in infants and young children and the death rate may be very high among those infants who develop TB. By contrast, children between around 7 and 12 years of age have the lowest risk of any age group of developing active TB. Even where culture and other facilities are available, diagnosis of childhood TB is difficult. Sputum smears are usually negative in children with PTB.

      A history of close contact with a smear-positive pulmonary TB case is essential information.

      A positive TST is also strongly suggestive of TB in a child with unexplained illness, particularly in younger children in whom the background rate of TST positivity is low.

      Scoring systems have been developed to rationalize the diagnosis of childhood TB none has been well validated, but they may provide useful guidance.

      An aid to diagnosis of TB in children

      • Score chart for child with suspected TB

      Score

      0

      1

      3
      Length of illness <2 weeks 2–4 weeks >4 weeks
      Weight for age >80% 60–80% <60%
      Family TB (past or present) None Reported by family Proved sputum +ve

       
      • Score for other features if present:
      Positive tuberculin skin test (TST) 3
      Large painless lymph nodes: firm, soft, and/or sinus in neck, axilla, and groin 3
      Unexplained fever, night sweats, no response to malaria treatment 2
      Malnutrition, not improving after 4 weeks 3
      Angle deformity of the spine 4
       Joint swelling, bone swelling, or sinuses 3
      Unexplained abdominal mass or ascites 3
      CNS: change in temperament, convulsions, or coma 3

       
      • If the TOTAL score is 7 or more  treat for TB

      Treat children with a score less than 7 if:

      • CXR is characteristic of TB infection, or
      • The child does not respond to two 7-day courses of two different antibiotics

    Footnote

    2 Dr Keith Edwards, University of Papua New Guinea, published in Crofton et al. (1997) Clinical tuberculosis, MacMillan

    Diagnosis

    Sputum smears

    Three sputa should be examined whenever a cough has been present for >2–3 weeks. In patients who travel some distance to the clinic, the 1st specimen is collected at first presentation, the 2nd is an early morning sputum collected at home on the day the patient returns for follow up, and the 3rd is collected in clinic that day.

    In patients who cannot produce sputum, or in suspected PTB with repeated negative sputum smears, induction with 3% hypertonic saline significantly improves the sensitivity of smear and culture. Gastric lavage is useful in children, where culture facilities are available.

    Chest X-ray

    CXR is not routinely necessary for the diagnosis and management of TB. A normal CXR makes PTB unlikely, but CXRs cannot distinguish reliably between TB and other diseases or between changes of current and past TB. The interpretation of CXR varies according to the skill of the reader and between readers. They do not predict infectiousness (as the sputum smear does), nor supply the definitive identification provided by culture. CXR is useful in patients with undiagnosed chest symptoms who are repeatedly smear negative.


    Tuberculin skin testing (TST)

    Relies on the fact that cell-mediated hypersensitivity typically develops within 8 weeks of infection with M. tuberculosis. The test involves intradermal injection of PPD (purified protein derivative). The diameter of skin induration (swelling; not redness) is measured at 48–72 hours. Training and experience in interpreting skin test responses is critical to achieving accurate results. In most situations, 10 mm of induration to a standard tuberculin dose is the cut-off point between positive and negative; 5 mm is considered to be positive in an HIV-infected individual. Both false negative and false positive TST results occur commonly. The stronger the TST response, the less likely it is to be a false positive.

    Uses of the TST

    • Epidemiologic determining prevalence or incidence in populations or specific groups such as health care workers.
    • Diagnostic to aid in assessing the likelihood of TB as the cause of a clinical illness. In high-prevalence countries, this use is largely limited to children because of the high background prevalence of TST positivity in the adult population.
    • Determination of candidates for ˜chemoprophylaxis (e.g. paediatric contacts of pulmonary TB patients, HIV-infected individuals).
    Lowenstein-Jensen medium used for growing Myco...

    Lowenstein Jensen culture media for TB culture

     

    The Mantoux skin test consists of an intraderm...

    The Mantoux Test


    Diagnosis of sputum-negative PTB

    Reassessment and repeat sputum examination after 2–3 weeks, following a therapeutic trial of a broad-spectrum antibiotic, may clarify the diagnosis. CXR, interpreted with the cautions mentioned below, may help to estimate the likelihood of TB in suspects who remain smear-negative.

    Before diagnosing smear-negative PTB, consider alternative

    diagnoses such as:

    Pneumonia  Bronchiectasis
    Asthma Lung abscess
    Chronic bronchitis Lung cancer
    Non-TB respiratory complications of HiV infection

     

    In some TB programmes, a decision to start treatment for smear-negative PTB can only be made by a doctor or individual with particular expertise in TB.

    A therapeutic trial of treatment

    A therapeutic trial is widely used by some practitioners to diagnose TB. Therapeutic trials have not been validated, and this approach risks creating confusion among health care workers. If therapeutic trials are to be used, then:

    • All efforts to make a diagnosis should have been exhausted.
    • The endpoint used to determine success or failure should be established before starting treatment and should be objective (eg. fever, weight gain).
    • The duration of the trial should be established at the beginning: fever can be expected to settle within 14 days of starting treatment in most cases, and weight gain should be evident by 4 weeks.
    • The drugs used for the trial should have antimycobacterial activity (isoniazid, ethambutol, and pyrazinamide) but not be effective against other infections (rifampicin and streptomycin)
    • The patient’s status as a trial patient should be clearly established in the local TB programme.

    A false positive TST can be caused by:

    • BCG: TST response following BCG is variable; BCG in infancy is unlikely to account for a strongly positive TST in adulthood
    • Exposure to environmental mycobacteria
    • Incorrect interpretation

    A false negative TST can be caused by:

    • Normal variation
    • Long interval since infection
    • Reduced cell-mediated immune response (HIV, old age, corticosteroid therapy, measles, malnutrition)
    • Severe illness, including overwhelming TB
    • Incorrect TST technique or interpretation

    Treatment

    Aims of treatment

    • To cure the patient.
    • To prevent transmission in the patient’s family and community.
    • To prevent development of resistant bacilli.

    Principles of anti-TB therapy

    • Use at least 2 drugs to which the organism is presumed to be sensitive.
    • Administer treatment for an adequate duration (6–8 months with the regimens used in most national TB programmes).
    • Ensure that each patient completes the full course of therapy with a high level of adherence.

    First- and second-line anti-TB drugs (see box )

    Treatment is the same regardless of disease site, although some advise a prolonged consolidation phase for TB meningitis and bone disease (12 months total). Anti-TB drugs should be provided in the form of fixed-dose combination (FDC) tablets which make monotherapy impossible and provide a further defence against the development of drug resistance.

    Anti-TB drug dosage and standard regimens

    Most national TB programmes have a standard regimen and a re-treatment regimen — the latter for patients who have defaulted, failed treatment, or relapsed.

    Anti-TB drug (abbreviation)

    Recommended dose (mg/kg)

    od

    3 × week
    Isoniazid (H) 5 10
    Rifampicin (R) 10 10
    Pyrazinamide (Z) 25 35
    Streptomycin (S) 15 15
    Ethambutol (E) 15 30
    Thiacetazone (T) 2.5 N/A

     

    First-line regimen (WHO) 2HRZE 4HR or 2HRZE 4H3R3

    • Isoniazid, rifampicin, pyrazinamide, and ethambutol for 2 months
    • Followed by isoniazid and rifampicin either  or 3×/week for4 months

    First-line regimen (International Union against Tuberculosis and Lung Disease)

    2HRZE 6HE

    • Isoniazid, rifampicin, pyrazinamide, and ethambutol od for 2 months
    • Followed by isoniazid and ethambutol od for 6 months

    Re-treatment regimen (defaulters, treatment failure, relapse).

    2HRZES 1eHRZE 5H3R3E3

    • Isoniazid, rifampicin, pyrazinamide, ethambutol, and streptomycin od for 2 months
    • Followed by isoniazid, rifampicin, pyrazinamide, ethambutol od for 1 month
    • Followed by isoniazid, rifampicin, ethambutol 3×/week for 5 months

    Anti-TB drugs

    • Isoniazid (INH): potent anti-TB activity. Main serious adverse effect is liver toxicity.
    • Rifampicin (rifampicin): essential to the success of modern short course TB therapy (<12 months). Rifampicin is characterized by a high rate of drug interactions (induces liver enzymes and lowers serum levels of warfarin, anticonvulsants, oral contraceptives, some antiretrovirals, etc). It can cause hepatitis.
    • Pyrazinamide: sterilizing activity allows treatment courses of 6 months. May cause vomiting, arthralgias, less commonly hepatitis. Contribution to first-line regimens limited largely to the first 2 months of therapy
    • Ethambutol: main role is prevention of resistance to other drugs, particularly when 1° resistance to one or more first-line agents is possible. Main serious adverse effect is ocular toxicity, which is uncommon at recommended doses.
    • Thiacetazone: formerly used in conjunction with isoniazid in the continuation phase. Largely abandoned in high HIV-prevalence countries because of high rates of Stevens Johnson syndrome in HIV-co-infected patients.
    • Streptomycin: now limited to second-line or re-treatment regimens because of the cost of needles and syringes and the desire to avoid unnecessary injections in the HIV era. Ototoxicity (vertigo >hearing loss) and renal toxicity are the main adverse effects. The drug should be avoided or dosage adjusted carefully in renal dysfunction. Contraindicated in pregnancy.

    Special groups

    • Isoniazid causes peripheral neuropathy more commonly in diabetic, malnourished, alcoholic, and pregnant patients; and in those with pre-existing neuropathy. Give pyridoxine 10–15 mg/d to prevent peripheral neuropathy.
    • Women on oral contraceptives must use another form of contraception (e.g. an IUD) during rifampicin therapy and for 4–8 weeks after stopping rifampicin.
    • Pregnancy: TB drugs, except for streptomycin, may be used in pregnancy. Any theoretical risks to the fetus are much less than the risks from untreated TB.

    Third-line anti-TB drugs

    Recently, some programmes have acquired anti-TB drugs for the treatment of multidrug-resistant (MDR) TB. Treatment of MDR TB is much longer (>18 months), much more toxic, much more costly, and considerably less effective than treatment of drug-sensitive TB. Therefore it must only be introduced in settings where a DOTS (directly observed therapy, short course) programme is established and demonstrating good outcomes. MDR TB treatment requires supervision of every treatment dose, a well-structured programme with guidelines, appropriate laboratory resources, assured drug supply, and access to expert advice, as recommended by the WHO ˜Green Light Committee

    Monitoring treatment:

    Sputum-positive patients should be monitored by sputum smear examination after 2 months of treatment and prior to treatment completion. All other patients should be monitored clinically. Monitoring for adverse drug reactions is essential.

    Concordance: patients usually feel better soon after starting treatment, so may lose the motivation to continue therapy for many months. Treatment completion is essential for cure and prevents the development of drug resistance. The treating health care worker and the TB programme must ensure that patients complete TB therapy. This is most likely to succeed if the patient and community are active and informed participants and aware of the risks of drug resistance. The relationship between the patient and program or clinic staff is a major factor promoting concordance.

    Resistance: small numbers of M. tuberculosis are mutants naturally resistant to single TB drugs. Combination chemotherapy ensures that these resistant organisms will be killed by other drugs. Poor choice of treatment or poor concordance with therapy results in selection for these resistant organisms.

    Treatment failure: follow guidelines in the national TB manual or the re-treatment regimen.

    TB control

    Smear-positive PTB patients transmit infection. Curing smear-positive cases is the 1° means of reducing TB transmission in the community.

    Once availability and quality of treatment have been established, the next priority is case finding. This activity must be integrated with the primary health care service since it depends upon recognition and appropriate investigation (most importantly by sputum smear examination) of TB suspects by primary health care workers.

    Bacille Calmette Guerin (BCG):

    is a live attenuated vaccine derived from M bovis. Protective efficacy ranges from 0 to 80% for reasons which remain controversial. BCG provides some protection against miliary TB and TB meningitis, and should be given at birth to all children in high TB-prevalence countries (except those with symptomatic HIV disease). BCG has little or no impact on the rate of infectious TB in a community.

    Household and close contacts of TB cases: Symptomatic contacts should be investigated for active TB. Chemoprophylaxis should be offered to asymptomatic household contacts aged <5 years, of smear-positive PTB patients. In high-prevalence countries, HIV prevention is an important form of TB control.

    Cross-infection control

    Health care workers are exposed to a significant occupational risk of TB, and HIV-infected subjects are at very high risk. The important infection control principles are:

    • Early diagnosis and treatment of patients to minimize the period of infectiousness.
    • Encourage patients to cover their mouths when coughing or sneezing.
    • Early identification and respiratory isolation of TB suspects pending diagnosis.
    • Increased natural ventilation and sunlight in TB wards and clinics.
    • Encourage health care workers to be tested for HIV and employ those with HIV where there is lower risk of TB exposure (e.g. non-clinical jobs, paediatrics).

    Wearing of common surgical masks by staff provides very limited protection against TB. The infectious droplets are too small to be blocked by these masks and the masks do not seal around the mouth.

    In the laboratory, most TB risk occurs in handling of TB cultures. The risk in handling specimens and preparing sputum smears is much lower.

    Patients should cough sputum specimens in a separate, well-ventilated area. Wearing of masks by lab staff is not needed.

    TB and HIV

    TB incidence has increased up to 6-fold in some communities affected by the HIV pandemic. HIV prevalence is up to 80% among TB patients in these places. TB is the most common cause of death in patients with HIV. The main mechanism involved is suppression of cell-mediated immunity (CD4 helper T-cells and macrophages) by HIV which impairs the immune response to TB.

    Differences in management of TB in HIV +ve patients

    Presentation: most patients with HIV-related TB do not know their HIV status. Some have clinical features of HIV infection: oral candidiasis, chronic diarrhoea, skin and hair changes, peripheral neuropathy, herpes zoster scars, etc. However, since TB can occur early during the course of immune suppression, other clinical features of HIV are often absent.

    Extrapulmonary TB is common in HIV +ve patients, particularly lymphadenopathy, pleural and pericardial effusions, miliary TB, and meningitis. However, PTB continues to be the most common form of TB.

    The radiographic appearance of PTB in HIV +ve patients sometimes differs from the classical appearances, roughly according to the individual’s degree of immune suppression. HIV +ve patients less commonly have upper lobe disease and cavities and more commonly have hilar adenopathy, effusions, and miliary and nodular shadowing.

    Diagnosis: sputum smear microscopy is slightly less sensitive in HIV +ve patients. Differential diagnosis of lung disease in the HIV +ve includes:

    • Bacterial (most often pneumococcal) pneumonia: a short history and a response to antibiotic therapy is suggestive.
    • Pneumocystis jiroveci pneumonia: it is less common in some tropical settings but characteristic features are a history of cough and fever for weeks, severe dyspnoea and hypoxia, diffuse changes on X-ray, and a response to high-dose co-trimoxazole therapy.
    • Pulmonary Kaposi’s Sarcoma: most patients have cutaneous or mucosal lesions (e.g. on the hard palate).

    Treatment regimens:

    The same drug regimens are used in HIV +ve and uninfected patients, so knowledge of HIV status is not required to provide anti-TB treatment. Sputum conversion rates and initial cure rates are similar in HIV +ve patients and those without HIV provided modern rifampicin-containing regimens are used.

    Recurrence rates and re-infection rates are higher. Mortality during and after treatment is markedly increased among patients with HIV, with most deaths being due to HIV-related causes other than TB.

    Increasing numbers of patients have access to ART. Treatment with anti-TB and antiretroviral drugs can lead to complex and clinically important drug interactions:

    • Rifampicin reduces serum levels of most protease inhibitors and some non-nucleoside reverse transcriptase inhibitors such as nevirapine.
    • Immune reconstitution reactions can result in temporary clinical deterioration when ART is started early in the course of TB treatment.

    One strategy is to delay ART until completion of the intensive phase of TB treatment and use of a non-rifampicin-containing continuation phase such as 6 months of isoniazid and ethambutol. Seek expert advice if ART and TB therapy are to be given together.

    There are potential benefits to patients with HIV and TB from giving prophylaxis with co-trimoxazole. Consult national guidelines on this issue. Compared to HIV uninfected people, persons with HIV have:

    • A much higher risk of progressive primary disease following infection.
    • A much higher risk of reactivation of latent TB infection — about 10% per year (compared to 10% in a lifetime in HIV uninfected people).
    • After successful treatment of TB, an increased risk of re-infection with a new strain of M. tuberculosis.

    TB increases HIV replication and may enhance progression to AIDS.

    Treatment of latent TB infection in HIV-infected patients:

    HIV +ve individuals, who are also TST-positive and who have no evidence of active TB disease, have significantly less risk of developing active TB if given chemoprophylaxis though the benefit declines with time, especially if the patient continues to live in a community where the risk of is high. TB transmission Isoniazid for 6-9 months is standard, and seems not to cause increased isoniazid resistance.

    Large-scale chemoprophylaxis programmes for people with HIV are uncommon in practice. Care must be taken that anti-TB drugs, especially rifampicin, are not used or distributed in ways that could promote development of resistance.

    HIV testing of TB patients:

    TB patients are a sentinel group, often selected for epidemiologic surveillance of the HIV epidemic. When treating individual patients, there is an ethical obligation to inform patients when strong clinical evidence of HIV infection is found and to provide them with the option of serologic testing to confirm or exclude HIV.

    Whether all TB patients should be offered HIV testing should be determined at local or national level based on availability of testing and counseling resources and care for HIV infection, policies regarding voluntary testing and counseling, anticipated local reaction in relation to stigmatization of TB patients, and other local factors.

    Oxford Handbook of Tropical Medicine, 2nd Edition

    //

Unusual MR presentations of Pyogenic Spondylodiscitis –

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Unusual MR presentations of Pyogenic Spondylodiscitis –

H.S.Das N. Medhi, P.Sarma, P.Goswami, , P.Hazarika.

Infective (Pyogenic and tubercular) spondylitis is a relatively common entity in day-to-day practice. Though commonest cause of such infection is tuberculosis in our country, pyogenic infection of the spine is also frequently encountered. Majority of these pyogenic infections of the spine are iatrogenic in nature, though in some cases the cause and source of infection cannot be ascertained. We report 4 patients of infective spondylodiscitis with unusual presentations.

Case-1: 43 yrs female patient had laparoscopic cholecystectomy in a local hospital. She was nondiabetic and nonhypertensive and blood examination revealed mild anemia and slight rise in the TSH. After surgery was uneventful and she was kept in the intensive care unit overnight and sent to the paying ward after 24 yrs. Her immediate postoperative status was perfectly all right. On 2nd postoperative night she developed excruciating pain and she got partial relief of pain after putting her on continuous parenteral analgesics. Though her pain remained unaltered she was discharged on the 4th day only with analgesics. As pain did not subside an MR examination of the cervical spine was performed. MRI showed significant loss of cervical lordosis with hazy epidural space and provisionally the treatment was continued as cervical sprain. She continued to have pain and later on she developed difficulty in lifting the head. Second MR was performed on 3rd week due to detorioration of her condition and showed evidence of spondylodiscitis at C5-C6 level. She was provisionally put on antibiotics (amikacin 500 mg iv x2weeks followed orally for 6weeks).

Case no 2. 35 yrs old patient had tonsillectomy for chronic tonsillitis. The surgery was carried under general anaesthesia and it was uneventful as far as the primary disease is concerned. He was non-diabetic and nonhypertensive. On third postoperative day the patient developed severe pain in the neck with out significant radicular pain. He was discharged from the hospital with simple analgesic without significant improvement in the condition of the neck pain. As patient deteriorates further an MR examination was performed. MR study reveals involvement of the C5-C6 disc by T2 hyperintense collection, marrow edema involving C5 and C6 vertebral bodies, prevertebral and epidural soft tissue collection. Due to significant compression of the cord surgery was performed to relive the compression and to get a histological diagnosis. At surgery the involved bones were very soft and infected material was removed from the site. Bacteriological and histological diagnosis was pyogenic infection and culture shows growth of pseudomonas infection. The organisms were sensitive to amikacin and gentamycin. Patient improved after surgery.

Case. No 3: 28 yrs female patient had CS under GA. The patient was not diabetic and nonhypertensive. Her pre operative blood and other laboratory parameters were grossly normal. The patient developed severe pain in the neck on 3rd postoperative day. She was also managed by rest and analgesics thinking it to be cervical spondylosis. As her status remains same in spite of rest and analgesics she was investigated by cervical MR. The MR showed features of spondylodiscitis at C5-C6 level with significant thecal compression by the epidural soft tissue component. There was prevertebral abscess also. As her condition continues to deteriorates decompressive surgery was performed. At surgery thick pus with granulation tissue was removed and sent for biopsy and bacteriological study. At pathology features were suggestive of pyogenic spondylodiscitis with salmonella infection. The organisms were sensitive to ciprofloxacin group of antibiotics and not very sensitive to the amikacin and gentamycin. She was put on parenteral antibiotics for 2weeks followed by oral antibiotics for 6weeks. She was completely free from all symptoms.

Case 4: 30 yrs female patient had undergone CS operation. She developed severe pain in the neck on third day of her surgery. Though she was treated with neck exercise and analgesic she continued to deteroriorate and an MR examination was called for. MR study of the cervical spine reveals evidence of spondylodiscitis at C5-C6 vertebral body with epidural and prevertebral collection with mild cord impingement. She was treated was lost to follow up.

Important observations:

- All the patients were operated in the same hospital.

- All 4 patients were operated within the month of June and July. No such patients were reported before or after this period.

- The surgeons were different in all of the cases.

- All patients had involvement of the C5-C6 levels.

- Clinical presentation and course of the disease were almost similar.

Discussion:

Spondylitis is a condition where there is primary infection of the vertebral body. Disc space involvement is called discitis. Pure vertebral osteomyelitis or discitis is infrequent and most of the time there is involvement of both vertebrae and disc hence term spondylodiscitis is preferred. The third element of the spinal infection is the epidural abscess, which is also frequently associated with spondylodiscitis.

Types of spondylodiscitis: According to the offending organism the spondylodiscitis may be pyogenic or Tubercular, though rarely other organisms like Brucella, Fungal or parasites may cause spondylodiscitis.

Pyogenic spondylodiscitis
Pyogenic infection of the spine can occur by three routes- hematogenous spread, direct inoculation and contiguous spread.

Though apparent source of infection in a patient with spondylodiscitis can not be traced even after through check up in most of the patients, the common source of hematogenous spread is from infections of the urinary tract, lungs, pelvis and skin. IV injections may be the source of infection in some patients developing spondylodiscitis after surgery. In diabetics and immuno-compromised patients, a spinal infection is relatively more frequent. The disc is directly infected in children in hematogenous route due to persistence of peridiscal blood vessels. But in adult the disc is avascular and is secondarily affected.

Pyogenic spondylodiscitis can occur by direct inoculation of the disc or contiguous spread of infection. A major proportion of this type of infection is iatrogenic. Iatrogenic disc space infection is most commonly encountered following spinal surgery. This is true in our experience also, where majority of pyogenic spondylodiscitis is due to lumbar disc surgery. This is due to various factors -firstly the lumbar disc surgeries are relatively common; secondly UTI and other pelvic infections frequently involve the lumbar spine. Majority of pyogenic infections are due to staphylococcus aureus and enterobacter group. Other organisms causing pyogenic spondylodiscitis are salmonella and serratia etc.

MR findings- MRI is the single most valuable imaging technique in evaluation of pyogenic spondylodiscitis. MRI can pick up the changes at the earliest stage so that these patients can be treated soon and hence the morbidity is significantly reduced. Involved vertebral bodies reveal increased signal intensity on T2 weighted images and reduced signal intensity on T1 weighted images due to marrow edema. The intervertebral disc reveal reduced signal intensity on T1 weighted images and strong / very strong signal intensity on T2 weighted images sometimes called “hot disc”. There is irregularity in the vertebral end plates with destruction sometimes.
In more advanced cases there is progressive destruction of the vertebral bodies. There is prevertebral soft tissue and epidural lesions in advanced cases.

Tubercular Spondylodiscitis: TB spondylodiscitis most commonly occurs by hematogenous route and generally affects all age groups. The vertebral body is primarily involved with secondary involvement of the appendages, disc and epidural space. There may be involvement of the cord also producing intra-medullary tuberculoma. Lower thoracic and upper lumbar vertebrae are more commonly affected.

MRI findings MR usually pick up the findings very early. There is involvement of two contiguous vertebral bodies including the disc. Involvement of more than two vertebral bodies and areas of skip lesions are frequently encountered. The involved vertebral bodies reveal reduced signal intensity on T1 weighted images and appear iso to hyperintense on T1 weighted images. There is involvement of the posterior elements and lot of epidural granulation tissue or frank collection is seen. Arachnoiditis and intra-medullary tuberculomas may be found.

click to see picture: tb-spine-photo

MR findings of TB Vs Pyogenic spondylodiscitis

  1. Disc space involvement is common in pyogenic infection. The disc becomes hyperintense on T2 weighted images classically described as “hot disc”.
  2. In tubercular infection the posterior elements are also involved which is uncommon in hematogenous pyogenic infection.
  3. More than two vertebral body segments are frequent in TB and there are skip lesions in some cases.
  4. Epidural space, spinal meninges and cord involvement more frequent in TB than pyogenic infection.

Other infections:

Other uncommon causes of spondylodiscitis are Brucella, fungal and rarely parasitic. Brucella spondylitis is characterized by erosion of the anterior aspect of the superior end plate. There is significant sclerosis along with lytic lesions. In fungal spondylitis the responsible organisms are blastomycosis, cryptococcosis and coccidiomycosis. There are destructive lesions, paravertebral soft tissue mass, multiple sites of involvement and relative sparing of the disc are some of the features of fungal spondylodiscitis.

Conclusion: MRI plays a vital role in diagnosis and management of spondylodiscitis. It has highest sensitivity in diagnosis such cases, where it can characterize most of these patients. Unusual presentation of infective spondylitis may cause confusion in diagnosis; FNAC or biopsy may be necessary in some of these patients. Difficulties may arise in differentiating spondylodiscitis with type-1 end plate change, where contrast study may be helpful. Similar problems may arise in cases where infection co-exists in pre existing tumor, where biopsy will give the final diagnosis.

Anatomy of the Cerebral Venous System & Dural sinuses

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Anatomy of the Cerebral Venous System & Dural sinuses

Authors: Himadri S. Das, P.Hatimota, P.Hazarika, C.D.Choudhury,

Institution: Matrix, 1st Byelane Tarun Nagar, G.S.Road, Guwahati-5

cerebral venous sinus anatomy.paper IRIA 2009.ghy

Address for Correspondence:

Dr Himadri Sikhor Das, MD, PDCC

Matrix, 1st Byelane Tarun Nagar

, G.S.Road, Near Rajiv Bhawan

Guwahati-781005

Tel:+0361-2464969

Email: drhsdas@gmail.com

Abstract:

Cerebral venous system can be divided into superficial and deep systems. The superficial system comprises of sagittal sinuses and cortical veins and these drain superficial surfaces of both cerebral hemispheres. The deep system comprises of lateral sinus, straight sinus and sigmoid sinus along with draining deeper cortical veins. Both these systems mostly drain themselves into internal jugular veins. The veins draining the brain do not follow the same course as the arteries that supply it. Generally, venous blood drains to the nearest venous sinus, except in the case of that draining from the deepest structures, which drain to deep veins. These drain, in turn, to the venous sinuses. The superficial cerebral veins can be subdivided into three groups. These are interlinked with anastomotic veins of Trolard and Labbe. However, the superficial cerebral veins are very variable. They drain to the nearest dural sinus.  The superolateral surface of the hemisphere drains to the superior sagittal sinus while the posteroinferior aspect drains to the transverse sinus. The veins of the   posterior fossa are variable in course and angiographic diagnosis of their occlusion is extremely difficult. Blood from the deep white matter of the cerebral hemisphere and from the

basal ganglia are drained by internal cerebral and basal veins, which join to form the great vein of Galen that drains into the straight sinus. With the exception of wide variations of basal vein, the deep system is rather constant compared to the superficial venous system. Hence their thrombosis is easy to recognize.

Key Words: Cerebral veins, MR, Venogram, thrombosis, TOF

Introduction

Cerebral venous system can be divided into two basic components.

A) Superficial System;

The superficial system comprises of sagittal sinuses and cortical veins and these drain superficial surfaces of both cerebral hemispheres.

B) Deep System;

The deep system comprises of lateral sinus, straight sinus and sigmoid sinus along with draining deeper cortical veins. Both these systems mostly drain themselves into internal Jugular veins.

A) Superficial cerebral venous system

The superficial cerebral veins (Figure1 and 2) can be divided into three collecting systems. First, a mediodorsal group draining into superior sagittal sinus (SSS) and the straight sinus (SS); Second, a lateroventral group draining into the lateral sinus; and third, an anterior group draining into the cavernous sinus. These veins are linked by the great anastomotic vein of Trolard, which connects the SSS to the middle cerebral veins. These are themselves connected to the lateral sinus (LS) by the vein of Labbe. The veins of the posterior fossa may again be divided into three groups:

1) Superior group draining into the Galenic system,

2) Anterior group draining into Petrosal sinus and

3) Posterior group draining into the torcular Herophili and neighboring transverse sinuses.

The veins of the posterior fossa are variable in course and angiographic diagnosis of their occlusion is extremely difficult. The Superior Sagittal Sinus (SSS) (Figure 3) starts at the foramen caecum and runs backwards towards the internal occipital protuberance, where it joins with the straight sinus and lateral sinus to form the torcular Herophili. Its anterior part is narrow or sometimes absent, replaced by two superior cerebral veins that join behind the coronal suture.

This fact should be borne in mind while evaluating for cerebral venous thrombosis (CVT). The SSS drain major part of the cerebral hemispheres. The cavernous sinuses drain blood from the orbits, the inferior parts of the frontal and parietal lobes and from the superior and inferior petrosal sinuses. Blood from them flow into the internal jugular veins.

The straight sinus is formed by the union of inferior sagittal sinus and the great vein of Galen. The inferior sagittal sinus runs in the free edge of falx cerebri and unites with the vein of Galen to form the straight sinus. It runs backwards in the center of the tentorium cerebelli at the attachment of the falx cerebri, emptying into the torcular Herophili at the internal occipital protuberance.

The lateral sinuses extend from torcular Herophili to jugular bulbs and consist of a transverse and sigmoid portion. They receive blood from the cerebellum, the brainstem and posterior parts of the hemisphere. They are also joined by some diploic veins and small veins from the middle ear. There are numerous LS anatomic variations that may be misinterpreted as sinus occlusion.

B) Deep cerebral venous system

The deep cerebral veins are more important than superficial veins from the angiographic point of view. Three veins unite just behind the interventricular foramen of Monro to form the internal cerebral vein (Figure 4). These include choroid vein, septal vein and thalamostriate vein. The Choroid vein runs from the choroid plexus of the lateral ventricle. The Septal vein runs from the region of the septum pellucidum in the anterior horn of the lateral ventricle and the thalamostriate vein runs anteriorly in the floor of the lateral ventricle in the thalamostriate groove between the thalamus and lentiform nucleus. The point of union of these veins is called the venous angle.

Revised diagram of cranial sinuses (in the hum...


The internal cerebral veins of each side run posteriorly in the roof of the third ventricle and unite beneath the splenium of the corpus callosum to form the great cerebral vein. The internal cerebral veins, which lie within 2 mm of the midline, are the most important deep veins since they can be used to diagnose midline shifts. The great cerebral vein of Galen is a short (1-2 cm long), thick vein that passes posterosuperiorly behind the splenium of corpus callosum in the quadrigeminal cistern. It receives the basal veins and the posterior fossa veins and drains to the anterior end of the straight sinus where this unites with the inferior sagittal sinus.

The basal vein of Rosenthal begins at the anterior perforated substance by the union of anterior cerebral vein, middle cerebral vein and the striate vein. The basal vein on each side passes around the midbrain to join the great cerebral vein. In summary, blood from the deep white matter of the cerebral hemisphere and from the basal ganglia, is drained by internal cerebral veins and basal veins of Rosenthal, which join to form the great vein of Galen that drains into the straight sinus (Figure 2). With the exception of wide variations of basal vein, the deep system is rather constant compared to the superficial venous system so their thrombosis is easy to recognize.

Specific features of Cerebral Venous System in Pathophysiology

of Cerebral Venous Thrombosis

The cerebral veins and sinuses neither have valves nor tunica muscularis. Because they lack valves, blood flow is possible in different directions. Moreover, the cortical veins are linked by numerous anastamoses, allowing the development of a collateral circulation and probably explaining the good prognosis of some cerebral venous thromboses. Lack of tunica muscularis permits veins to remain dilated. This is important in understanding the huge capacity to compensate even an extended occlusion. Venous sinuses are located between two rigid layers of duramater. This prevents their compression, when intracranial pressure rises. Superficial cortical veins drain into SSS against the blood flow in the sinus, thus causing turbulence in the blood stream that is further aggravated by the presence of fibrous septa at the inferior angle of the sinus.

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This fact explains greater prevalence of SSS thrombosis. In addition to draining most of the cerebral hemisphere, the superior sagittal sinus also receives blood from diploic, meningeal and emissary veins. Same is the case with other dural venous sinuses. This explains the frequent occurrence of CVT as a complication of infective pathologies in the catchments areas e.g. cavernous sinus thrombosis in facial infections, lateral sinus thrombosis in chronic otitis media and sagittal sinus thrombosis in scalp infections. The dural sinuses especially the SSS contain most of the arachnoid villi and granulations, in which absorption of CSF takes place. So dural sinus thrombosis blocks villi and leads to intracranial hypertension and papilloedema.

References

1. Sutton D., Stevens J.: Vascular Imaging in Neuroradiology in Textbook of radiology and Imaging, volume 2 by Churchill Livingstone New York 2003, pp1682-87.

2. Ryan S.P., Mc Nicholas M.M.J., Central Nervous system in Anatomy for diagnostic Imaging by W.B. Saunders Company Ltd. London. 1998, pp 77-80.

3. Kido DK, Baker RA, Rumbaugh Calvin L. Normal Cerebral Vascular Anatomy. In: Abrams Angiography, Vascular and Interventional Radiology by Abrams HL, Third Edition. Little, Brown and Company, Boston. USA. 1983 pp 257-68.

4. Meder JF, Chiras J. Roland J, Guinet P, Bracard S, Bargy F. Venous territories

of the brain. J Neuroradiol 1994; 21:118 – 33.

5. Einhaupl KM, Masuhr F.Cerebral Venous and Sinus thrombosis – an update Eur J Neurol 1994; 1: 109 – 26.

6. Huang, Y.P., and Wolf, B.S. Angiographic features of fourth ventricle tumors with special reference to the posterior inferior cerebellar artery. Am J Radiol. 1969; 107:543.

7. Hacker H: Normal Supratentorial veins and dural sinuses. In: Newton TH, Potts DG, eds: Radiology of Skull and Brain. Angiography. Book 3. St Louis: Mosby; 1974; 2:1851-77.

8. Weissleder R., Wittenberg J. Neurological Imaging in Primer of Diagnostic Imaging, Third Edition. Philadelphia: Mosby 2003: p 492.

9. Krayenbuhl HA, Yasargil MG. Cerebral Angiography (2nd ed.). London: Butterworth 1968.10. Dora F and Zileli T: Common Variations of the lateral and occipital sinuses at the confluence sinuum. Neuroradiology 1980; 20 : 23 – 7.

11. Taveras J.M..: Angiography in Neuroradiology Third Edition. Baltimore: Williams & Wilkins. 1996 pp 998.

12. Wolf, B.S., Newman, C.M. and Schlesinger, B. The diagnostic value of thedeep cerebral veins in cerebral angiography. Am J Radiol. 1962; 87:322.

13. Wolf B S, Huang Y P, Newman C.M. The superficial Sylvian venous drainage system. Am J Radiol. 1963; 89:398.

14. Wolf B S, Huang YP. The subependymal veins of the lateral ventricles. Am J Roentgenol Radium Ther Nucl Med. 1964; 91:406-26.

15. Parkash C, Bansal BC. Cerebral venous thrombosis. J Indian Acad Clin Med. 2000; 5: 55 – 61.

16. Kalbag RM, Woolf AL. Etiology of cerebral venous thrombosis in cerebral venous thrombosis publ. Ed Kalbagh RM, Wolf AL. Volume1. Oxford University Press London, 1967; pp 238.

17. Wasay M, Azeemuddin M. Neuroimaging of Cerebral Venous thrombosis. J Neuroimaging 2005; 15:118-28.

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Getting Started in Clinical Radiology – From Image to Diagnosis

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Getting Started in Clinical Radiology – From Image to Diagnosis

Functional Magnetic Resonance Imaging (fMRI) in Neuroradiology:

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Functional Magnetic Resonance Imaging (fMRI) in Neuroradiology:

Dr Himadri S.Das

First, the most commonly used fMRI technique called BOLD-fMRI (Blood-Oxygen-Level-dependent fMRI) potentially offers imaging with a temporal resolution on the order of 100 milliseconds and a spatial resolution of 1-2 millimeters, which is much greater than that of PET and SPECT scanning. This means that transient cognitive events can potentially be imaged and small structures like the amygdala can be more readily resolved. Most fMRI techniques are noninvasive and do not involve the injection of radioactive materials so that a person can be imaged repeatedly. This allows imaging of a patient repeatedly through different disease states or developmental changes Third, with fMRI, one can easily make statistical statements in comparing different functional states within an individual in a single session. Thus, fMRI may be of important use in understanding how a given individual’s brain functions and perhaps, in the future, making psychiatric diagnoses and treatment recommendations. It is in fact already starting to being used in presurgical planning to map vital areas like languages, motor function, and memory.

The four main applications of MRI for functional information can be categorized as :-

1. BOLD-fMRI which measures regional differences in oxygenated blood.

2. Perfusion fMRI which measures regional cerebral blood flow.

3. Diffusion-weighted fMRI which measures random movement of water molecules and

4. MRI spectroscopy, which can measure certain cerebral metabolites noninvasively.

1. BOLD-fMRI (Blood-Oxygen-Level-Dependent fMRI)

BOLD-fMRI is currently the most common fMRI technique

With this technique, it is assumed that an area is relatively more active when it has more oxygenated blood compared to another point in time. This is based on the principle that when a brain region is being used, arterial oxygenated blood will redistribute and increase to this area. This principle has one limitation: there is a time lag of 3-6 seconds between when brain region is activated and blood flow increases to it . During this time lag of 3-6 second, in fact, the activated areas experience relative decrease in oxygenated blood as oxygen is extracted by the active regional neurons. Afterward, the amount of blood flowing to the area far out weighs the amount of oxygen that is extracted so that oxygenated blood is now higher. Although images can be acquired every 100 msecs with echoplanar (a type of rapid acquisition) BOLD fMRI, this predictable but time varied delayed onset of the BOLD response limits the immediate temporal resolution to several seconds instead of the 100 msec potential. In the future, researchers may be able to improve the temporal resolution of fMRI by measuring the initial decrease in oxygenated blood with activation.

BOLD fMRI is a relative technique in that it must compare images taken during one mental state to another to create a meaningful picture. As images are acquired very rapidly (ie. a set of 15 coronal brain slices every 3 seconds is commonly) one can acquire enough images to measure the relative differences between two states to perform a statistical analysis within a single individual. Ideally, these states would differ in only one aspect so that everything is controlled for except the behavior in question.

BOLD fMRI paradigms generally have several periods of rest alternating with several periods of activation. Images are then compared over the entire activation to the rest periods. Images obtained over the first 3 to 6 seconds of each period are generally discarded due to the delay in hemodynamic response. Alternating paradigms are used because the signal intensity generated by the MRI scanner drifts with time.

fMRI BOLD is best used for studying processes that can be rapidly turned on and off like language, vision, movement, hearing and memory. The study of emotion is hampered by its slow and variable onset and its inability to be quickly reversed. Some have, however, succeeded in using this technique to study emotional processes.

BOLD fMRI is very sensitive to movement so that tasks are limited to those without head movement, including speaking. BOLD fMRI is also limited in that artifacts are often present in brain regions that are close to air (ie. sinuses). Thus there are some problems in observing important emotional regions at the base of the brain like the orbitofrontal and medial temporal cortices. Another problem is that sometimes observed areas of activation may be located more in areas near large draining veins rather than directly at a capillary bed near the site of neuronal activation. Neurologists and neurosurgeons are beginning to use this technique clinically to noninvasively map language, motor and memory function in patients undergoing neurosurgery.

Two fMRI methods have been developed for measuring cerebral blood flow. The first method, called intravenous bolus tracking, relies on the intravenous (iv) injection of a magnetic compound such as a gadolinium-containing contrast agent and measuring its T2 weighted signal as it perfuses through the brain over a short time period of time.

Areas perfused with the magnetic compound show less signal intensity as the compound creates a magnetic inhomogeneity that decreases the T2 signal. The magnetic compound may be injected once during the control and once during the activation task and relative differences in blood flow between the two states may be determined to develop a perfusion image. Alternatively one can measure changes in blood few over time over time after a single injection to generate a perfusion map.

Although gadolinium-based contrasts are not radioactive, the number of boluses that can be given to an individual is limited by the potential for kidney toxicity with repeated tracer administration. This technique also only generates a map of relative cerebral blood flow, not absolute flow as in the text technique. Arterial spin labeling is a T1 weighted noninvasive technique where intrinsic hydrogen atoms in arterial water outside of the slice of interest are magnetically tagged (“flipped”) as they course through the blood and are then imaged as they enter the slice of interest.

Arterial spin labelling is noninvasive, does not involve an IV bolus injection, and can, thus, be repeatedly performed in individual subjects. Also, absolute regional blood flow can be measured which cannot be easily measured with SPECT or BOLD fMRI and requires an arterial line with PET. As absolute information is obtained, cerebral blood flow can be serially measured over separate imaging sessions such as measuring blood flow in bipolar subjects as they course through different disease states. Absolute blood flow information may be important in imaging such processes as anxiety which may be hard to turn on and off. For instance, in social phobics, a relaxation task may be imaged on one day and anticipating making a speech may be imaged on the next day. Comparing these separate tasks in different imaging sessions would not be possible with BOLD fMRI. Arterial spin labelling has some limitations in that it takes several minutes to acquire information on a single slice of interest. Therefore, one must have a specific brain region that one is interested in examining. Also, as it currently takes several minutes to acquire a single slice, it would be tedious obtaining enough images on this slice within a single session to make a statistical statement on a given subject.

2. Diffusion-Weighted Imaging (DWI)

Diffusion-weighted imaging is very sensitive to the random movement of 1 H in water molecules (Brownian movement). The amount of water diffusion for a given pixel can be calculated and is called the apparent diffusion coefficient (ADC). Areas with low ADC value (ie. low diffusion) appear more intense. ADC values are direction sensitive. For instance, if images are taken perpendicular to myelin fiber tracts like the optic chiasm, arcuate fasciculus, or corpus callosum, ADC values will be lower than if the images are taken along the length of these fibers. This is thought to because there is little diffusion across myelin sheaths. Thus, ADC direction sensitivity permits detection of Myelination and may allow researchers to understand in greater detail myelin development in infants. On the other hand, this direction sensitivity hampers the study of diffusion in other processes as ADC values differ, depending on the imaging plane (axial, coronal or sagittal). There are now ways to calculate average ADC values incorporating all planes for each pixel, removing “artifacts” due to the direction of acquisition. Removing the directional diffusion sensitivity has been helpful in studying stroke.

While it is currently unclear now diffusion-weighted imaging will be useful in studying psychiatric disorders, it hold great promise for changing the clinical management of acute ischaemic stroke by potentially refining the criteria for patients most likely to benefit from thrombolytic therapy.

3. MRI Spectroscopy (MRS):

MRI spectroscopy (MRS) offers the capability of using MRI to noninvasively study tissue biochemistry. In the conventional and functional MRI techniques listed. The hydrogen atom in water is the main one that is flipped (resonated). In MRS, either 1H atoms in other molecules or other atoms such as 31P, 23Na, K, 19F or Li are flipped. Within a given brain region called a voxel, information on these molecules is usually presented as a spectrograph with precession frequency on the x-axis revealing the identity of a compound and intensity on the y-axis, which helps quantify the amount of a substance. The quantity of a substance is related is related to the area under its spectrographic peak; the larger the area, the more of a substance that is present.

The reason why several molecules can be identified and quantified within a single scan is that the resonant magnetic pulse has a bandwidth over a narrow precession frequency range os that it can flip several molecules at once. The signal intensity at each of these precession frequencies can then be identified using a complicated mathematical procedure called a Fourier transform. For a given precession frequency (or spectrographic peak of a given molecule), information can also be presented spatially as metabolic maps which are created with similar principles to the 1H atom in water spatial map in conventional MRI. The spatial resolution of these maps is generally less than that of conventional MRI as the substance concentration is much less than that of water. Consequently, the minimum area needed to obtain a visible signal is greater.

The two most widely used MRS techniques involve either viewing 1H atoms in molecules other than water or 31P-containing molecules. In 1H MRS, the water signal must first be suppressed as it is much greater than the signal from other 1H-containing compounds and has overlapping spectroscopic peaks with compounds.

Compounds that can be resolved with 1H-MRS include:

a) N-acetylaspartate (NAA) which is though to be a neuronal marker that decreases in processes where neurons die;

b) Lactate which is a product of anaerobic metabolism and may indicate hypoxia;

c) Excitatory neurotransmitters glutamate and aspartate;

d) The inhibitory neurotransmitter gamma-amino butyric acid (GABA);

e) Cytosolic choline which includes primarily mobile molecules involved in phospholipid membrane metabolism but also small amounts of the neurotransmitter acetylcholine and its precursor choline;

1. Myolinositol which is important in phospholipoid metabolism and intracellular second messenger systems; and

2. Creatine molecules such as creatine and phosphocreatine which usually have relatively constant concentrations throughout the brain and are often used as relative reference molecules (ie. one may see NAA concentration reported as the ratio NAA/creatine in the literature).

Phosphorus (31P) MRS allows the quantification of ATP metabolism, intracellular pH, and phospholipid metabolism. Mobile phospholipid, including phosphomonoesters (PME – putative cell membrane building blocks) and phosphodiesters (PDE – putative cell membrane breakdown products) can also be measured, supplying information on phospholipid membrane metabolism.

MRS is an useful tool to be used in the characterization of tumor, stroke and epileptogenic tissue and in presurgical planning.

Limitations

MRS is restricted to studying mobile magnetic compounds. As neurochemical receptors are noted usually mobile, they cannot be measured with MRS. Thus, receptor-ligand studies in psychiatry are still the domain of SPECT and PET. Another problem with MRS is that due to the low concentrations of many of the imaged substances, larger areas than with water are needed to obtain detectable signals. Larger volume units imaged over longer periods are thus used with this technique, limiting both temporal and spatial resolution compared with conventional MRI and BOLD-fMRI. However, stronger magnetic fields which can spread out precession frequencies over a wider range may improve this resolution.

Conclusions

While there are currently no clinical indications for ordering any of these fMRI techniques, they hold considerable promise for unraveling the neurocircuitry and metabolic pathways of numerous disorders in the immediate future and in further helping in diagnosis and treatment planning.

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Contrast Media Administration Guidelines by the ACR (American College of Radiology) Version 6 – 2008

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Contrast Media Administration Guidelines by the ACR (American College of Radiology) Version 6 – 2008

Lumbarization or sacralization-?. Concept of lumbosacral transitional vertebra

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Lumbarization or sacralization-?. Concept of lumbosacral transitional vertebra by MRI

Lumbosacral transitional vertebrae (LSTV) occur when the last lumbar vertebra shows elongation of its transverse process, with varying degrees of fusion to the first sacral segment. The term “LSTV” is used to avoid having to decide whether such a vertebra is a “sacralized L5″ or a “lumbarized S1.” Although LSTV can be sensitively identified on sagittal lumbar spine MRI, based on abnormal morphology of the lumbosacral junction  no standard method is established for their numbering. Techniques that have been used include the addition of cervicothoracic localizer scans and determining lumbar levels by identification of the right renal artery(in relation to the L1-2 disk space ). These techniques are prone to substantial error.Both anatomic and MRI studies have indicated that the iliolumbar ligament (ILL) arises almost exclusively from the L5 transverse process  However, these studies are limited by relatively small numbers  .if ILLs can be reliably identified on routine axial MR images through thelumbosacral junction and if they arise solely from L5, then their level of origin can serve as a marker of lumbar levels, which may enable the confident numbering of LSTV.
The ILLsappear as either a single or a double hypointense band arising from the transverse process and extending to the posteromedial aspect of the iliac crest.  If an LSTV is present, it is numbered as a transitional L5 or transitional S1 segment based on the following method. When the ILL  arises at
the level above the LSTV, the vertebral level of origin of the ILL was labeled L5 and, consequently, the LSTV was numbered S1 . If the ILL is not visualized, the LSTV is numbered L5  This numbering system was based on the hypothesis that in the presence of healthy lumbosacral segmentation, the ILL always arises from L5

and is therefore a marker of the L5 level.

Using identification of the iliolumbar ligaments as a marker of the L5 vertebral level, we can number LSTV as L5 transitions and S1 transitions. The iliolumbar ligament is readilyidentifiable on axial lumbar spine MRI and always arises from L5.We suggest that its position can be used to confidently assign lumbar levels in patientswith LSTV.

Unusual MR presentations of Pyogenic Spondylodiscitis –

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tb-spine-photo

Unusual MR presentations of Pyogenic Spondylodiscitis –

H.S.Das N. Medhi, P.Sarma, P.Goswami, , P.Hazarika.

Infective (Pyogenic and tubercular) spondylitis is a relatively common entity in day-to-day practice. Though commonest cause of such infection is tuberculosis in our country, pyogenic infection of the spine is also frequently encountered. Majority of these pyogenic infections of the spine are iatrogenic in nature, though in some cases the cause and source of infection cannot be ascertained. We report 4 patients of infective spondylodiscitis with unusual presentations.

Case-1: 43 yrs female patient had laparoscopic cholecystectomy in a local hospital. She was nondiabetic and nonhypertensive and blood examination revealed mild anemia and slight rise in the TSH. After surgery was uneventful and she was kept in the intensive care unit overnight and sent to the paying ward after 24 yrs. Her immediate postoperative status was perfectly all right. On 2nd postoperative night she developed excruciating pain and she got partial relief of pain after putting her on continuous parenteral analgesics. Though her pain remained unaltered she was discharged on the 4th day only with analgesics. As pain did not subside an MR examination of the cervical spine was performed. MRI showed significant loss of cervical lordosis with hazy epidural space and provisionally the treatment was continued as cervical sprain. She continued to have pain and later on she developed difficulty in lifting the head. Second MR was performed on 3rd week due to detorioration of her condition and showed evidence of spondylodiscitis at C5-C6 level. She was provisionally put on antibiotics (amikacin 500 mg iv x2weeks followed orally for 6weeks).

Case no 2. 35 yrs old patient had tonsillectomy for chronic tonsillitis. The surgery was carried under general anaesthesia and it was uneventful as far as the primary disease is concerned. He was non-diabetic and nonhypertensive. On third postoperative day the patient developed severe pain in the neck with out significant radicular pain. He was discharged from the hospital with simple analgesic without significant improvement in the condition of the neck pain. As patient deteriorates further an MR examination was performed. MR study reveals involvement of the C5-C6 disc by T2 hyperintense collection, marrow edema involving C5 and C6 vertebral bodies, prevertebral and epidural soft tissue collection. Due to significant compression of the cord surgery was performed to relive the compression and to get a histological diagnosis. At surgery the involved bones were very soft and infected material was removed from the site. Bacteriological and histological diagnosis was pyogenic infection and culture shows growth of pseudomonas infection. The organisms were sensitive to amikacin and gentamycin. Patient improved after surgery.

Case. No 3: 28 yrs female patient had CS under GA. The patient was not diabetic and nonhypertensive. Her pre operative blood and other laboratory parameters were grossly normal. The patient developed severe pain in the neck on 3rd postoperative day. She was also managed by rest and analgesics thinking it to be cervical spondylosis. As her status remains same in spite of rest and analgesics she was investigated by cervical MR. The MR showed features of spondylodiscitis at C5-C6 level with significant thecal compression by the epidural soft tissue component. There was prevertebral abscess also. As her condition continues to deteriorates decompressive surgery was performed. At surgery thick pus with granulation tissue was removed and sent for biopsy and bacteriological study. At pathology features were suggestive of pyogenic spondylodiscitis with salmonella infection. The organisms were sensitive to ciprofloxacin group of antibiotics and not very sensitive to the amikacin and gentamycin. She was put on parenteral antibiotics for 2weeks followed by oral antibiotics for 6weeks. She was completely free from all symptoms.

Case 4: 30 yrs female patient had undergone CS operation. She developed severe pain in the neck on third day of her surgery. Though she was treated with neck exercise and analgesic she continued to deteroriorate and an MR examination was called for. MR study of the cervical spine reveals evidence of spondylodiscitis at C5-C6 vertebral body with epidural and prevertebral collection with mild cord impingement. She was treated was lost to follow up.

Important observations:

- All the patients were operated in the same hospital.

- All 4 patients were operated within the month of June and July. No such patients were reported before or after this period.

- The surgeons were different in all of the cases.

- All patients had involvement of the C5-C6 levels.

- Clinical presentation and course of the disease were almost similar.

Discussion:

Spondylitis is a condition where there is primary infection of the vertebral body. Disc space involvement is called discitis. Pure vertebral osteomyelitis or discitis is infrequent and most of the time there is involvement of both vertebrae and disc hence term spondylodiscitis is preferred. The third element of the spinal infection is the epidural abscess, which is also frequently associated with spondylodiscitis.

Types of spondylodiscitis: According to the offending organism the spondylodiscitis may be pyogenic or Tubercular, though rarely other organisms like Brucella, Fungal or parasites may cause spondylodiscitis.

Pyogenic spondylodiscitis
Pyogenic infection of the spine can occur by three routes- hematogenous spread, direct inoculation and contiguous spread.

Though apparent source of infection in a patient with spondylodiscitis can not be traced even after through check up in most of the patients, the common source of hematogenous spread is from infections of the urinary tract, lungs, pelvis and skin. IV injections may be the source of infection in some patients developing spondylodiscitis after surgery. In diabetics and immuno-compromised patients, a spinal infection is relatively more frequent. The disc is directly infected in children in hematogenous route due to persistence of peridiscal blood vessels. But in adult the disc is avascular and is secondarily affected.

Pyogenic spondylodiscitis can occur by direct inoculation of the disc or contiguous spread of infection. A major proportion of this type of infection is iatrogenic. Iatrogenic disc space infection is most commonly encountered following spinal surgery. This is true in our experience also, where majority of pyogenic spondylodiscitis is due to lumbar disc surgery. This is due to various factors -firstly the lumbar disc surgeries are relatively common; secondly UTI and other pelvic infections frequently involve the lumbar spine. Majority of pyogenic infections are due to staphylococcus aureus and enterobacter group. Other organisms causing pyogenic spondylodiscitis are salmonella and serratia etc.

MR findings- MRI is the single most valuable imaging technique in evaluation of pyogenic spondylodiscitis. MRI can pick up the changes at the earliest stage so that these patients can be treated soon and hence the morbidity is significantly reduced. Involved vertebral bodies reveal increased signal intensity on T2 weighted images and reduced signal intensity on T1 weighted images due to marrow edema. The intervertebral disc reveal reduced signal intensity on T1 weighted images and strong / very strong signal intensity on T2 weighted images sometimes called “hot disc”. There is irregularity in the vertebral end plates with destruction sometimes.
In more advanced cases there is progressive destruction of the vertebral bodies. There is prevertebral soft tissue and epidural lesions in advanced cases.

Tubercular Spondylodiscitis: TB spondylodiscitis most commonly occurs by hematogenous route and generally affects all age groups. The vertebral body is primarily involved with secondary involvement of the appendages, disc and epidural space. There may be involvement of the cord also producing intra-medullary tuberculoma. Lower thoracic and upper lumbar vertebrae are more commonly affected.

MRI findings MR usually pick up the findings very early. There is involvement of two contiguous vertebral bodies including the disc. Involvement of more than two vertebral bodies and areas of skip lesions are frequently encountered. The involved vertebral bodies reveal reduced signal intensity on T1 weighted images and appear iso to hyperintense on T1 weighted images. There is involvement of the posterior elements and lot of epidural granulation tissue or frank collection is seen. Arachnoiditis and intra-medullary tuberculomas may be found.

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MR findings of TB Vs Pyogenic spondylodiscitis

  1. Disc space involvement is common in pyogenic infection. The disc becomes hyperintense on T2 weighted images classically described as “hot disc”.
  2. In tubercular infection the posterior elements are also involved which is uncommon in hematogenous pyogenic infection.
  3. More than two vertebral body segments are frequent in TB and there are skip lesions in some cases.
  4. Epidural space, spinal meninges and cord involvement more frequent in TB than pyogenic infection.

Other infections:

Other uncommon causes of spondylodiscitis are Brucella, fungal and rarely parasitic. Brucella spondylitis is characterized by erosion of the anterior aspect of the superior end plate. There is significant sclerosis along with lytic lesions. In fungal spondylitis the responsible organisms are blastomycosis, cryptococcosis and coccidiomycosis. There are destructive lesions, paravertebral soft tissue mass, multiple sites of involvement and relative sparing of the disc are some of the features of fungal spondylodiscitis.

Conclusion: MRI plays a vital role in diagnosis and management of spondylodiscitis. It has highest sensitivity in diagnosis such cases, where it can characterize most of these patients. Unusual presentation of infective spondylitis may cause confusion in diagnosis; FNAC or biopsy may be necessary in some of these patients. Difficulties may arise in differentiating spondylodiscitis with type-1 end plate change, where contrast study may be helpful. Similar problems may arise in cases where infection co-exists in pre existing tumor, where biopsy will give the final diagnosis.

BRIEF REVIEW OF PULMONARY IMAGING IN CRITICALLY ILL PATIENTS:-

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BRIEF REVIEW OF PULMONARY IMAGING IN CRITICALLY ILL PATIENTS:-

Dr Himadri S. Das

Matrix, Guwahati

Imaging plays an important role in assessment and daily management of acute life threatening conditions in critically ill patients with multi-systemic involvement. Modalities which are used for primarily for pulmonary imaging include x-rays (mostly using portable equipment with low mA), USG (using portable bedside units), transesophageal Doppler and CT scans. The availability of multislice CT scanners has reduced the problem of breath holding and patient motion with faster imaging times. Most of the critically ill patients usually can not obey commands, can not hold breath or be properly positioned and above all are under life support systems or ventilated with numerous tubes, catheters and lines .Role of Imaging is increasing in the intensive care setting. A brief review pertaining to pulmonary imaging in critically ill patients is outlined below.

Normal tubes, lines and catheters: Radiography should be done after insertion of tube or line to see correct position and identify complications. Iatrogenic problems from malpositioned lines are common and may be life threatening.

Normal findings:-

  1. Endotracheal tube (ET) – Normal ET tube tip should be 3 to 5 cm above carina. In neutral head and neck position the tube is seen 3 to 5 cm above carina. If the cervical spine is flexed the ET tube may descend 2 cm so the tube tip is seen at 3 to 5 cm from carina. If the cervical spine is extended there is 2 cm ascent of the tube tip which is seen 7 to 9 cm from carina. Ideally the tube width should be at least 2/3rd of the width of trachea. The cuff of the tube should not bulge the tracheal wall.
  2. Nasogastric (NG / feeding) Tube: – For suction of fluid in supine position proper location of tip should be in fundus of stomach. For suction of air in supine position proper location should be in antrum of stomach.
  3. Tracheostomy tube: – For patients requiring long term intubation. Tube tip should be above carina. Tube width should be 2/3rd the width of trachea.
  4. Chest tube: – For pneumothorax in supine patient, the tube should be placed antero-superiorly ideally. For hydrothorax in supine patient the tube should be placed postero-inferiorly. For empyema and haemothorax CT may help to plan drainage. Early drainage is important. Poor drainage will lead to fibrothorax and patients may require decortication.
  5. Central venous catheter (central line):- To maintain optimal blood volume or long term drug administration. Ideal position is in distal SVC. Access may be obtained from internal jugular, antecubital or femoral veins.
  6. Swan Ganz catheter: – To measure pulmonary capillary wedge pressure. Reflects LA and LV end diastolic volume. Ideal position is in the right or left pulmonary artery. Same access as above.
  7. Surgically implanted catheters: - For long term venous access usually for antibiotics or chemotherapy. Reservoir is placed in anterior chest wall soft tissues. Catheter tip ideally in distal SVC.

Abnormal tubes, lines and catheter’s:- CT may be helpful when complications are suspected.

a) Endotracheal tubes :- (a) Malposition: – May be intubated into right mainstem bronchus causing atelectasis of left lung. Bronchus intermedius intubation may cause atelectasis of left lung and right upper lobe. If there is 100 % inspired oxygen there may be immediate atelectasis with bronchial occlusion.

a) Esophageal intubation: – may cause dilated stomach with poor lung volumes.

b) Vocal cord injury if tip is at the level of larynx.

c) Sinusitis with nasotracheal intubation.

d) Barotrauma: – Alveoli are over distended and may rupture from high peak pressure with mechanical ventilation. Others: – Interstitial emphysema, pneumomediastinum and or pneumothorax.

e) Aspiration pneumonia: – 5 to 10 ml of fluid may pool above the ET cuff. Deflation and aspiration may potentially develop into pneumonia. Suspected if normal air above cuff is replaced by soft tissue density.

f) Tracheostenosis: – Late complication. At stoma, tip or multiple foci. At tip usually occurs 1.5 cm below stoma.

g) Tracheomalacia: – Late complication.

b) Tracheostomy Tube: – Cuff may be in subcutaneous tissues with tissue necrosis. Over inflation of cuff or deflection of tip may lead to tracheoesophageal fistula or into artery or vein producing haemorrhage.

c) Nasogastric tube: – Into bronchus, lung or pleura. Signs: – Consolidation occurs if fluid is administered. Atelectasis if occluding air way and pneumothorax if penetrating lung.

d) Chest tubes: Poor position and inadequate drainage if tube is in the interlobar fissures. If in the chest wall the outer wall of the chest tube is not visible. If in the lung may cause bronchopleural fistula. Side hole in chest wall may cause massive subcutaneous emphysema. The tube tip impacting artery (example – Subclavian) or esophagus may result in injury / erosion.

e) Central venous catheter: (a). Malposition: – Into Subclavian, aorta or femoral artery. Through vein wall into pleura or mediastinum. Into myocardium or pericardium. Retrograde into a jugular vein, rarely into liver.

(b). Pneumothorax, mediastinal haematoma after placement.

(c). Catheter break and embolism. Aseptic or septic thrombus on catheter with pulmonary embolization.

(d). Fibrin sheath occlusion.

(e). Thrombosis of vein: – Directly related to period of catheterization and potential source for pulmonary emboli.

f) Swan Ganz catheter:-pulmonary infarction from wedged catheter with of without clot, and with or without inflated balloon tip. Arrhythmias may occur if tip is in right ventricle. Pulmonary artery pseudo aneurysm formation or rupture due to over distension of cuff in small pulmonary artery. Pseudo aneurysm is manifested as elliptical pulmonary nodule the long axis of which parallels the vasculature within 2 cm of hila, usually on right side. Pulmonary haemorrhage may occur if aneurysm ruptures.

g) Surgically implanted catheters: – Infection, septic emboli, thrombosis or torn catheter between clavicle and 1st rib felt as “osseous pinch”. Rotation of pulse unit in the soft tissues by the patient causing fracture or shortening of pacer lead ( twiddling sign )

Clinical issues and treatment:-

- Infected catheter may clear with antibiotic treatment without removal.

- Fibrin sheath-infuse tissue plasminogen activator, if unsuccessful then exchange catheter.

- Interventional snare retrieval for embolized catheter fragments.

- Infection most common complication of central venous catheter, usually staphylococcus.

- Fibrin sheath sign: – Catheter may be flushed but not aspirated.

DIFFUSE ALVEOLAR DAMAGE (DAD)

  • Diffuse peripheral pulmonary consolidation.
  • Lack of Kerley B lines and peribronchial cuffing.
  • Anterior (nondependent) cysts from barotraumas with positive end expiratory pressure (PEEP).
  • Acute respiratory distress syndrome (ARDS): Clinical definition, severe hypoxemia on high concentrations of O2, normal wedge pressure.
  • Seen with nearly any medical or surgical condition: Toxic fumes, aspiration, shock, postoperative, pancreatitis.
  • Pathophsiology : Inflammatory mediators damage capillary membrane
  • Etiology:
    • Nearly any major medical or surgical condition
      • Airway insult; aspiration (especially gastric acid); toxic fume inhalation; o2 toxicity; pneumonia.
      • Blood-borne insult; sepsis; transfusion; surgery; shock; eclampsia; pancreatitis.

Imaging Findings;

  • Best clue: Intubated patient with diffuse peripheral consolidation.

CXR:

  • Diffuse pulmonary consolidation.
  • Favors the lung periphery.
  • Kerley B lines infrequent (more frequent with cardiogenic edema)
  • Peribronchial cuffing infrequent.
  • Normal heart size: No pulmonary vascular redistribution.
  • May have small pleural effusions.
  • Initial use of PEEP may increase lung volume giving apparent radiographic “improvement”.
  • Barotraumas common with PEEP.
  • Superimposed pneumonia common.

CT / HRCT Findings.

  • Surprisingly inhomogenous.
  • Gravitational gradient: Ventral to dorsal increase in opacities.
  • Resolution, coarse reticular thickening and cyst formation in anterior (ventral, nondependent) lung.

Differential Diagnosis

General

  • Usually patients with ARDS rapidly intubated to support oxygenation even when severity of consolidation is mild. Rather than radiographic differentiation, clinical management based on Swan-Ganz catheter and pulmonary capillary wedge pressure (PCWP)

Cardiogenic Edema

  • Separation from cardiogenic pulmonary edema moderately successful. Absent Kerley B lines and peribronchial cuffing, peripheral predominance, Normal heart size, pleural effusions rare. No pulmonary vascular redistribution, normal vascular pedicle.

Pneumonia

  • May have identical radiographic findings, may result in ARDS.

Massive Aspiration

  • May have identical radiographic findings, may result in ARDS.

Hemorrhage

  • May have identical radiographic findings, patient often anemic

Clinical Presentation

  • Acute (immediate) or insidious (hours or days) after initiating event.
  • Dyspnea, tachypnea, dry cough, agitation, cyanosis.
  • ARDS clinical definition for ADA, PaO2 < 50 with F1O2 > 50%
  • Normal wedge pressure : Decreased lung compliance
  • May have no chest radiographic abnormalities in first 12 hours
  • Later, chest radiograph diffusely abnormal

Prognosis

  • High mortality rate
  • Survivors may have either restrictive or obstructive functional deficits.

ASPIRATION PNEUMONITIS:

  • Pulmonary inflammation due to aspiration of infected oropharyngeal secretions
  • Patients may be unconscious, post-operation, intubated or have gastro-esophageal disorders
  • Gravity-dependent opacities, usually bilateral, basal and perihilar
  • Recurrent pneumonias in chronic aspiration
  • Aspiration of gastric acid during labor and delivery can be server and fatal (Mendelson’s syndrome) Adults often have underlying conditions, e.g. neurologic disorders, alcoholism esophageal disorders, on mechanical ventilation, tracheoesophageal fistula

Imaging Findings

Best clue: Recurrent gravity-dependent opacities

CXR: Acute aspiration

o Gravity-dependent, patchy, multi-focal airspace opacities, usually bilateral (conversely may be unilateral) basal and peripheral

o Supine position; posterior segments of upper lobes or superior segments of lower lobes

o Airway findings from larger aspirated particles

§ Segmental or lobar atelectasis

§ Hyperinflation or air trapping more common in infants and children

o May worsen in first few days the clear rapidly

o Aspiration of large amounts of gastric common can progress to acute respiratory distress syndrome (ARDS)

o Complications: Necrotizing pneumonia, abscess, ARDS, pulmonary embolism.

  • Chronic aspiration
    • Recurrent opacities often in the same location, reticulonodular opacities, bronchiectasis, pulmonary fibrosis.

CT Findings

  • Airspace opacities in dependent lung, centrilobular nodules
  • Can be used to evaluate for complications of abscess, empyema

Differential Diagnosis

Pneumonia or Recurrent Pneumonias

  • Identical radiographic findings
  • Immunocompromised patient predisposed to recurrent pneumonias

Pulmonary Embolism

  • Identical radiographic findings
  • Infarcts peripheral, often with pleural effusion
  • Predisposing factors for thromboembolism

Pulmonary Edema

§ Cardiomegaly, pleural effusions

§ Kerley B lines uncommon with aspiration

AIDS

  • Identical radiographic findings
  • Aspiration predisposing factor for ARDS

Bronchiolitis Obliterans Organizing Pneumonia (BOOP)

  • Similar radiographic findings, may also wax and wane

Prognosis

  • Death rate for patients who develop ARDS from Mendelson’s syndrome is up to 50%.

ATELECTASIS (PULMONARY COLLAPSE):

  • Decrease in volume of lung or a portion of lung
  • Types : Obstructive, passive, cicatrizing and adhesive
  • Signs : Shift of fissures, mediastinum and hila toward collapse
  • Diagnosis can be made with chest radiography : CT to establish cause

Imaging Findings

  • Best clue : Displacement of fissures
  • Types of atelectasis
    • Obstructive, e.g. bronchial neoplasm, no air bronchograms
    • Passive e.g. pneumothorax or pleural effusion – lung volume loss in proportion to volume of occupied pleura space
    • Cicatrizing e.g. remote tuberculosis with volume loss due to scarring
    • Adhesive, e.g. ARDS collapse due to surfactant deficiency

  • Lobar Collapse
    • Airlessness of affected lobe, local increase in opacity
    • Total lung volume average = 6720 ml
    • Signs of atelectasis proportional to amount of volume loss
    • Crowding of vessels and bronchi in affected lobe
    • Displacement of fissures, mediastinum and hilum towards to collapse
    • Overinflation of remaining lobes
    • “Silhouette” sign – loss of air – soft tissue interface when collapsed lung abuts an adjacent soft tissue structres

CXR:

  • Right upper lobe (RUL) atelectasis (average volume RUL = 1140 ml)
    • Collapses superiorly and medially, loss of SVC interface and apical soft tissue capping
    • PA – lateral radiograph : Minor fissure displaced upward
    • Lateral : Superior aspect of major fissure displaced anteriorly
    • Central mass : “Reverse S sign of Golden”
    • Juxtaphrenic peak : Tent of diaphragm (due to upward retraction inferior accessory fissure)
  • Left upper lobe (LUL) atelectasis (average volume LUL = 1160 ml)
    • Collapses anteriorly, partial loss of left heart border, haze superimposed on left hilum
    • Lateral : Major fissure shifted anteriorly
    • Luftsichel sign : Superior segment of lower lobe causes a crescent lucency between the aortic arch and the atelectatic upper lobe
  • Right middle lobe (RML) atelectasis (average volume RML = 670 ml)
    • Collapses as a triangle toward the right heart border
    • PA : Obscuration of right heart border
    • Lateral : Thin triangle or pancake shape from anterior chest wall with apex towards hilum, inferior aspect of major fissure
  • Lower lobe atelectasis ( average volume LLL = 1550 ml, RLL 2000 ml)
    • Collapse posteriorly, medially and inferiorly
    • PA : Triangular opacity medial lung bases obscures diaphragms
    • Lateral : Posterior displacement of major fissure, vague opacity over lower thoracic spine
  • Right middle and lower lobe atelectasis
    • Similar to pleural effusion : Ill defined right heart border and diaphragm
    • Pathology involving bronchus intermedius
  • Right upper and right middle lobe atelectasis
    • Simulates left upper lobe atelectasis (double bronchus sign : 2 separate airways obstructed)
    • Borrie’s sump: Nodes between RUL and RML bronchus may obstruct both.
    • Bronchogenic carcinoma most common cause
  • Segmental and subsegmental atelectasis (plate atelectasis)
    • Long linear opacities are thicker and more indistinct than Kerley B lines
    • Indicates low volume states : common in critically ill or post-op-patients
    • Also seen with pulmonary embolism

  • Total lung atelectasis
    • Shift of mediastinum to opacity, hyperinflation of contralateral lung
    • Differentiating large pleural effusion : Mediastinal shift to opposite side
  • Round Atelectasis
    • Associated with pleural thickening (asbestos related) in lower lobes
    • Oval, wedge-shaped or irregular subpleural mass with air bronchograms (60%)
    • Comet tail sign (whorled bronchovascular markings into mass)
    • Most are stable for many years

CT Findings

  • Can help identify cause, i.e. bronchial obstructing lesion
  • No imaging can predict if the atelectatic lobe is sterile or infected
  • CT useful to exclude endobronchial lesion and confirm round atelectasis

Differential Diagnosis

Pneumonia

  • Radiographic opacity but no volume loss

Embolus

  • Peripheral opacity, volume loss of hemithorax due to splinting

Lung Cancer

  • Round atelectasis may simulate lung cancer
  • Endobronchial neoplasm common cause of lobar atelectasis in adult

General

  • Lobar obstruction, collapse in 18 to 24 hours if breathing room air
  • Lobar obstruction, collapse in < 5 minutes if breathing 100% oxygen
    • Nitrogen very slowly absorbed, delays development of atelectasis
  • Obstructed lobe may not collapse because of ventilation across the pores of kohn and canals of Lambert, or across incomplete fissures

Presentation

  • Asymptomatic fever can occur with atelectasis without infection
  • Left lower lobe collapse : Most common in ICU setting

CARDIOGENIC PULMONARY EDEMA

  • Common problem usually due to left heart failure
  • Stepwise progression from pulmonary venous hypertension to interstitial edema to alveolar edema.
  • Can clear rapidly with treatment.
  • Shifts gradually with position (gravitational shift test)

Imaging Findings

  • Best clue: Cardiomegaly with pulmonary venous hypertension and interstitial edema.

CXR:

  • Earliest radiographic manifestation: Upper lobe vessels are equal to or larger in diameter than lower lobe vessels; increased pulmonary artery / bronchus ratio in upper lobes, ill-defined lower lung vessels.
  • Interstitial edema – thickening of interlobular septa – Kerley A and B lines, lower zonal and perihilar haze, subpleural edema thickens interlobar fissures, peribronchial cuffing.
    • Kerley A : Long lines in upper lobes radiating towards hilum (rare)
    • Kerley B : Short, peripheral, perpendicular lines generally in lower lobes (common)
  • Alveolar edema – diffuse airspace opacification – gravity dependent
  • “Bat’s wing” (butterfly, perihilar) opacities (uncommon)
  • Small bilateral effusions, larger on right, rarely unilateral on the left
  • Cardiac enlargement chronically (normal heart with acute myocardial ischemia or arrhythmia)
  • In chronic obstructive pulmonary disease (COPD), the cardiac size is often small due to hyperinflation, subsequent increases in heart size may not be beyond the range of normal.
  • Azygos ± SVC distention (widened vascular pedicle)
  • Temporal relationship of pressure and volume
    • Acute pressure (capillary wedge pressure) elevation
      • Initially normal, edema accumulates over 12 hour period
    • Pressure decrease with treatment
      • Edema resolves hours to days; radiograph “lags” clinical course
  • Chest radiograph equivalents, smooth thickening of interlobular septa, bronchovascular bundle thickening, gravity-dependent ground-glass and / or airspace opacities.

Differential Diagnosis

Interstitial Edema: Pneumonia , Lymphangitic carcinomatosis

Alveolar Edema : Non cardiogenic edema, pneumonia , pulmonary hemorrhage

Alveolar proteinosis, acute eosinophillic pneumonia

Interstitial Edema, Cardiomegaly, Pleural Effusions

THE CHEST RADIOGRAPH FOLLOWING TRAUMA:

Soft tissues

Foreign bodies

Surgical emphysema

Ribs

Simple fracture May be associated with surgical emphysema, pneumothorax, extra- pleural haematoma or haemothorax. First rib fractures have a high incidence of other associated injuries.

Flail chest

Sternum:-

Fracture – May be associated with a clinically unsuspected dorsal spine fracture.

Sternoclavicular dislocation.

Clavicles and scapulae:-

Fracture – scapular fractures are usually associated with other bony or intrathoracic injuries.

Spine

Fracture – when present, are multiple in 10 % and non-contiguous in 80% of these. Thoracic spine injuries have a much higher incidence of neurological deficit than cervical or lumbar spine injuries.

Cord trauma.

Nerve root trauma - especially to the brachial plexus.

Pleura

Pneumothorax – simple (in 20-40 % of patients with penetrating injuries) or tension. Signs of a small pneumothorax on a supine chest radiograph include a deep costophrenic sulcus, basal hyperlucency, a “double” diaphragm, unusually clear definition of the right cardiophrenic angle or left cardiac apex and visualization of apical pericardial fat tags. CT is more sensitive than plain film radiography.

Haemothorax: in 25-50 % of patients with blunt chest trauma and 60-80 % of patients with penetrating wounds.

Lung

Contusion – non-segmental alveolar opacities which resolve in a few days.

Haematoma – usually appears following resolution of contusion. Round, well-defined nodule. Resolution in several weeks.

Aspiration pneumonia.

Foreign body

Pulmonary oedema – following blast injuries or head injury (neurogenic oedema).

Adult respiratory distress syndrome (ARDS) – widespread air space shadowing appearing 24-72 hours after injury.

Fat embolism

Trachea and bronchi

Laceration or fracture – initially surgical emphysema and pneumomediastinum followed by collapse of the affected lung or lobe.

Diaphragm

Rupture – in 3-7 % pf patients with blunt and 6-46% of patients with penetrating thoraco-abdominal trauma. Diagnosis may be delayed months of year. Plain film finding include herniated stomach or bowel above the diaphragm, pleural effusion, a supra-diaphragmatic mass or a poorly visualized or abnormally contoured diaphragm. Probable equal incidence on both sides but rupture of the right hemidiaphragm is not so easily diagnosed.

IMAGING OF ICU PATIENTS FOLLOWING THORACIC SURGERY:

Median sternotomy:-

CABG is the most commonly performed operation. Valve replacement surgery comes next. Incidence of complications is low. Main complications are rebleeding and mediastinitis. In patients with rebleed 20% are picked up radiologically. Rebleeding usually occurs in first 24 hours. CT is the best modality to show complications like osteomyelitis, dehiscence, abscess and mediastinitis. Mortality is upto 50% with complications. Dehiscence or mediastinitis may be asymptomatic or present with nonspecific chest pain, cough and fever. Usually occur 10 to 14 days after operation.

Findings:-

CXR: – Immediate recovery room film, expected findings are – Basal atelectasis (90%), Left > Right due to phrenic nerve cooling, weight of heart and difficulty to suction left lower lobe bronchus.

Edema (mild):- Cardiopulmonary bypass “pump lung”, anesthetic volume expansion and intrinsic left ventricular dysfunction.

Mediastinal bleeding: - Initial recovery room film for baseline width, may normally increase in width in first 24 hrs.

Sternal dehiscence: – May be normal. Vertical sternotomy incision > 3 mm width. Wire fracture incidental finding and not a finding of dehiscence.

CT is the best modality to show sternal irregularity, periosteal new bone formation, peristernal collections and infections, mediastinitis, retrosternal haematoma and edema. It is important to differentiate aortic dissection from rebleeding. Aortic dissection also causes mediastinal widening in post operative period. Clue is to look for displaced intimal calcification.

Thoracotomy and complications:-

Complications after lobectomy include atelectasis, pleural effusion, haemorrhage, air leak and infection. Potentially fatal complications include pulmonary embolism, cardiac herniation, lobar torsion, pneumonia, ARDS and respiratory failure.

Mortality is 2% and morbidity upto 40% after lobectomy. Normally there is ipsilateral mediastinal shift after pneumonectomy. With contralateral or no mediastinal shift consider bronchopleural fistula, haemorrhage, empyema in the post pneumonectomy. Mortality 6% and morbidity upto 60% after pneumonectomy.

Imaging findings:-

Post lobectomy normal findings: – Small amount of pleural fluid after drains are removed. Scattered lung opacities on the side of surgery. Effusion resolves during convalescence.

Post pneumonectomy normal findings: – 50 to 70 % of the hemithorax filled with fluid in 1 week. Complete filling with fluid in 2 to 4 months.

Normal mediastinal position: – Ipsilateral shift to the side of lobectomy. Returns to midline or close to midline as remaining lobes on the side of surgery hyper inflate. There is ipsilateral shift to side of pneumonectomy which is permanent.

Complications of lobectomy and pneumonectomy:-

Persistent pneumothorax, 10 to 20%.

Bronchopleural / bronchocutaneous fistula 2%.

Leak from suture line or bronchial stump: – Immediate post op period due to ischemia / infection.

Esophago-pleural fistula: – Most within 6 weeks of surgery due to adenitis, empyema or recurrent tumor.

Bronchial stump dehiscence: – Persistent pneumothorax, failure to fill with pleural fluid, drop in air fluid level of > 2 cm.

Hydrothorax: – Excessive pleural fluid. Consider poorly positioned chest tube, improperly positioned catheter with injection of fluid into pleura, thoracic duct injury and chylothorax.

Haemothorax: – Due to systemic, inter costal and mediastinal vessel laceration. Must be drained with chest tube or surgical ligation. Delay in treatment may result in fibrothorax and require decortication.

Empyema (< 5%):- Due to surgical contamination or from a bronchopleural fistula. Must be drained by chest tube. Delay results in fibrothorax, chronic empyema thoracic. Lung opacities seen in ICU patients are nonspecific from atelectasis and edema and is common in immediate post operative period.

Pneumonias: – Nosocomial, bronchopneumonia. Result of mechanical ventilation, narcotics, splinting, poor cough reflex and aspiration.

Elevated hemidiaphragm: – Consider phrenic nerve injury, atelectasis, pulmonary embolism or subphrenic abscess.

Cardiac herniation , pericardial defect :- Following intrapericardial pneumonectomy usually on right side, circulatory collapse, on right side there may be cardiac dextrorotation where cardiac apex lies against right chest wall “snow cone” appearance.

Left side – Cardiac levorotation

Post pneumonectomy syndrome (delayed complication)

After left pneumonectomy: Distal trachea and left main bronchus compressed between aorta and pulmonary artery.

After right pneumonectomy: Narrowed right upper lobe, bronchus intermedius and / or right middle lobe bronchi compressed between right pulmonary artery and spine

Torsion of a lobe or lung: After lobectomy. Remaining lobe rotates on its bronchovascular pedicle. 180-degree torsion leads to ischemia, infarction, and gangrene. Right upper lobectomy with torsion of right middle lobe is most common. Consider if abnormal position and orientation of pulmonary vessels are seen.

Herniation of lung through surgical defect in chest wall.: Accentuated by expiration.

References :

  1. Goodman LR et al: Congestive heart failure and adult respiratory distress syndrome. New insights using computed tomography. Radiol Clin North Am 34: 33-46, 1996.
  2. Ashbaugh DG et al : Acute respiratory distress in adults, Lancet 2 : 319-23, 1967
  3. Franquet T et al : Aspiration disease : Findings, Pitfalls, and differential diagnosis. Radiographics 20: 673-85, 2000
  4. Proto AV et al : Radiographic manifestations of lobar collapse. Semin Roentgenol 15: 117-73, 1980.
  5. Gluecker T et al : Clinical and radiologic features of pulmonary edema. Radiographic 19: 1507-31: 1999.
  6. Chest- top 100 diagnoses. Gurney JW, Wiener-Muram H,Amirys,2003,Reed Elsiever

Acute and non acute Schmorl’s nodes,disc vascularization : MR findings & recent concepts

Posted by Bobby on

 

Disc degeneration itself is a normal process in the elderly, beginning

as early in the twenties. There are 3 complications of degenerative disease of

the spinal column, making the normal process to a pathologic condition for

the individual : disc hemiation, spinal stenosis, and erosive osteochondritis.

MRI of erosive osteochondritis is characterized by disc vascularization and

bone marrow edema, both imaging features also found in infectious

spondylitis. Schmorl’s nodes can become vascularized like disc tissue in

erosive osteochondritis. There exist two types of Schmorl’s nodes: intraosseous

hemiation of nucleus pulposus tissue through the cartilaginous

endplate and hyaline cartilage proliferation originating in the trabecular bone

in erosive osteochondritis.

In disc degeneration, erosions of the adjacent vertebral endplates can be

present. However, the peripheral cortical bone of the vertebra is intact in disc

degeneration and frequently sclerosis can be found. Disc infections, on the

other hand, are frequently associated with destruction of the cortical borders

of the vertebra, the distinct dark rim of the endplate is then often focally not

visible on T1-weighted images. A gas density on CT is helpful to

distinguish degenerative disc vascularization in erosive osteochondritis from

spinal infection.

There is a high prevalence of degeneratively affected lumbar discs in MRI

examinations of people without back pain, and all degrees of disc

degeneration can be generally found in asymptomatic populations. However,

band-like vascularity in the disc space at the disco-vertebral junction is

associated with severe painful back syndromes . As bony changes and spurs at the endplates

are absent or only moderately developed segmental instability may play a causative role in

 the development of disc vascularity. Secondary disc vascularization represents a clinical condition

which can be diagnosed easily only by means of contrast enhanced MRI.

Therefore, MRI protocols in the work-up of patients with painful back

syndromes should include the application of paramagnetic contrast medium

and sagittal imaging planes after contrast medium injection, when previous

CT studies do not show disc herniation or other significant findings to explain

the patients symptoms. Degenerative disc vascularization is an important

differential diagnosis to bacterial spondylitis. It can be causative for pain in

patients with post-discectomy syndrome.

Gadopentetate dimeglumine enhanced MR imaging examinations of the

lumbar and thoracic spine is indicated for Schmorl’s nodes,

vascularization of Schmorl’s nodes, and associated bone marrow edema.

Sagittal T2-weighted SE and T1-weighted enhanced and non-enhanced SE

images with and without fat suppression  may be employed.

 

 

 

As the prevalence of Schmorl’s nodes decreases with age from youth to

adulthood, healing may be possible. Therefore, proliferative processes must

take place in the area of intraosseous herniation. At postmortem microscopic

examination, abnormal cartilage proliferation was noted in a 16 years old boy

with juvenile kyphosis in abnormal vertebrae and growth plates. In the

peripheral regions of the Schmorl’s nodes, where the vertebral bodies are in

contact with the node, growth of cartilaginous cells can occur. After

intraosseous herniation, ingrowth of vessels takes place from the adjacent

bone marrow into the periphery of the node and will progress to the center of

the node. It can be hypothesized that vascularization is requisite for cartilage

formation. Subsequent ossification contributes to sclerosis. By this

mechanism, sclerotic healing may be possible after ossification of the

cartilage.

 Only very few Schmorl’s nodes become symptomatic. Vascularity may be a

normal attempt to heal intraosseous cartilaginous hernias and is not

necessarily accompanied by back pain. However, enhancing Schmorl’s nodes

were bigger and more often accompanied by bone marrow edema in patients

with back pain than in those without. Enhancing Schmorl’s nodes should not

be confused with tumor or infection.

 

 

 

Suggested reading:

 

1.

Modic MT, Steinberg PM, Ross JS, Masaryk TJ, Carter JR
Degenerative disc disease: asessment of changes in vertebral bony
marrow with MR imaging.Radiology 1988; 166:193-199

 

2.Ross JS, Modic MT, Massaryk TJTears of the annulus fibrosus: assessment
with Gd-DTPA-enhanced MR imaging.AJR 1990; 154:159-162

 

3.Hamanishi C, Kawabata T, Yosii T, Tanaka SSchmorl’s nodes on
magnetic resonance imaging. Their incidence andclinical relevance.
Spine 1994; 19:450-453

 

4.Resnick D, Niwayama GIntravertebral disk herniations:
Cartilaginous (Schmorl’s) nodes.Radiology 1978; 126:57-65

 

5.Martel W, Seeger JF, Wicks JD, Washbum RLTraumatic lesions
of the discovertebral junction in the lumbar spine.Am J Roentgenol
1976; 127:457-464
6. Dr Axel Staebler, M.D. MR in D/D of disc space pathology :
Disc vascularization in acute degeneration ,
spondylitis,enhancing schmorls nodes :

MR case: Cervical Koch’s

Posted by Bobby on

case of cervical infective spondylodiskitis with concurrent intramedullary cord tuberculoma

MR MORPHOLOGY IN INTRACRANIAL TUBERCULOMAS

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MR Morphology of Intracranial Tuberculomas

Dr. H. S. Das, Dr. N. Medhi, Dr. B. Saharia, Dr. S. K. Handique

Introduction:

Tuberculomas represent a common neurological disorder in developing countries, forming 12-30% of all intracranial masses – (1,2). Furthermore the incidence of intracranial TB in patients with AIDS is also increasing, the highest incidence recorded being 2.3% – (3,4) in one study to 18% in another – (5). Prompt diagnosis is mandatory since any delay in increased morbidity and mortality. Unfortunately the diagnosis is not always possible on the basis of clinical and epidemiological data, since clinical manifestations are nonspecific – (7,8) and objective evidence of systemic tuberculosis or exposure to the disease may be absent in upto 70% of the cases – (9). The role of CT in diagnosis of CNS tuberculomas in well established, nevertheless CT findings should be interpreted with caution since neoplastic, fungal or parasitic diseases may cause similar changes on CT – (10). Recently Magnetic Resonance (MR) Imaging has shown advantage over CT in the detection of intracranial pathology – (11) and its value in the diagnosis of infections diseases of the central nervous system (CNS) has been reported – (12,13). Although tubercular meningitis can not be differentiated from other meningitides on the basis of MR findings; but intraparenchymal tuberculomas show characteristic T2 shortening not found in most other space occupying lesions – (14). Thus in the appropiate clinical setting tuberculomas should be considered. Here, we report our experience in using MR for the evaluation of patients with intracranial tuberculoma.

Patients and Methods:

10 Patients with intracranial tuberculomas were evaluated with MR in our institution between August ’95 to August’ 99. 8 males and 2 females between 5-45 years (Mean 22.9 years) were included in this study. MRI was performed on a 1-tesla super conductive magnet. Standard spin echo techniques were used to obtain multiplanar T1 and T2 weighted images. Contrast was used in 6 patients. The diagnosis of CNS tuberculosis was made after proper integration of data from the surgical and medical findings. Data included positive biopsy in 2 patients; analysis of blood and CSF (elevation in 2 cases); positive response to anti tubercular drugs in 6 patients and MR findings. Initial CT was done upon admission to the hospital in all ten cases. MR was done to visualize the full extent of the lesion, to differentiate these lesions from other diseases affecting the brain and to delineate the contents (necrotic centre, capsule and surrounding edema). None of the patients tested positive for HIV.

Results:

Tuberculomas were supratentorial in 9 patients and infratentorial in 1. All but one patient had single lesions, which were located at the cortico-subcortical junction of the cerebral hemispheres and in the brainstem in 2 patients. 1 patient had a cerebellar tuberculoma. On MR intracranial tuberculoma caused prolongation of the T1 relaxation time which was most marked at the centre of the lesion. 5 patients had lesions hypointense to normal brain; 4 patients had lesions isointense and 1 patient had a mixed signal with hypointensity predominating on T1 weighted images. On the T2 weighted sequences the MR appearance varied. In six patients the centre of the lesion gave hypointense (dark) signal while the periphery gave a hyperintense (bright) signal relative to the brain parenchyma due to surrounding oedema. In 2 patients the centre of the lesion was hyperintense with a hypointense rim surrounded again by diffuse hyperintensity due to edema.

Follow up CT in 6 patients during the course of antituberculous drugs showed reduction in the six of the lesion as well as the oedema as a result of therapy. 2 patients positive biopsy while 2 patients were lost to follow up. Following contrast infusion in 6 patients ring enhancing lesions were observed in 4 patients, disc enhancing lesion size of less than 1 cm, 3 patients had lesion size of more then 2 cms while the lesion size varied between 1-2 cms in the rest of the 6 patients. 2 out of the 10 patients presented with meningitis, which shows diffuse thick meningeal contrast enhancement presumably due to granulation tissue. These 2 patients also had different degrees of hydrocephalus.

Discussion:

Tuberculomas develop in the brain when the initial Rich’s focus does not rupture into the meninges but expands locally within the parenchyma due to greater resistance of host tissues to the infecting organism (5). Meningitis can cause borderline encephalitis resulting in direct infiltration of the brain parenchyma and multiple small tuberculomas which coalesce to form mature tuberculomas – (16).

Tuberculomas have different appearances on T2 weighted images depending on their stage of evolution. At an early stage of formation of tuberculomas, an inflammatory reaction occurs; the mass has an abundance of giant cells and a capsule poor in collagen. At this stage the mass is isointense on T1 and T2 weighted images. At a later stage, the capsule becomes rich in collagen. When small tuberculomas coalesce to become larger lesions they give low signal on T2 weighted images because of fibrosis, scar tissue and free radicals produced by macrophages during active phagocytosis – (17).

22 of the 27 cases (84%) of NCS tuberculoma in the literature clearly showed low signal on T2 weighted images – (8, 18, 19, 20). 5 (16%) had lesions with central high signal thought to represent caseating pathologic examination revealed tuberculoma with dense reactive fibrosis.

In another study out of 97 patients presumed to harbour cerebral tuberculomas (of which 11 were confirmed by biopsy and 73 showed a therapeutic response to AKT) the lesions were either homogenously hypointense or revealed a central hyperintense nidus within the hypointense lesion on T2 weighted images (21).

Based on a histopathological grading of 7 proven tuberculomas, Gupta et al (22) concluded that the signal intensity on T2 weighted images is variable and dependant on the relative proportion of macrophages, cellular infiltrates and fibrosis. Granulomas, which were frankly hyperintense on T2 weighted images, exhibited increased cellular infiltrates, scantly macrophages and little fibrosis; while the hypointense lesions showed grater numbers of macrophages; more fibrosis and gliosis – (22). Large amounts of lipids were reported to contribute to the T2 shortening in 2 of the granulomas analysed by localized proton spectroscopy – (22). MR is of value to visualize the full extent of the lesion, in differentiation of the lesion with other diseases of the CNS (e.g. fungal granuloma, haemorrhagic metastases and “granulo-nodular” stage of neurocysticercosis) and to delineate the different components of the lesion (necrotic center, capsule and surrounding oedema), which is not always possible with CT.

References:
1. Dastur HM, Desai AD (1965): A comparitive study of brain tuberculomas and gliomas based upon 107 case records of each. Brain 88: 375-396.
2. Laitha VS, Marker FE, Dastur DK, tuberculosis of the Central Nervous System. Neurology (India) 1980; 28: 197-201.
3. Anderson KM, MacMillan JI (1975) Intercranial Tuberculoma: an Increasing Problem in Britain. I. Neurolo Neurosurg Pshchiatry 38: 194-201.
4. Bishburg E, Sundaram G, Reichan LB; Kapila R (1986) CNS tuberculosis with AIDS its related complexes. Ann Intern Med 105: 210-213.
5. Intracranial tuberculosis is AIDS: CT and MRI findings. M.F. villomoria, J Dela Torre, F. Fortea, L. Munoz, T. Hernadez and J. J. Alarcon: (1992) Neuroradiology 34: 11-14.
6. Harder E, Al-Jawi MZ; Carney P (1983): Intracranial Tuberculoma; Conservative management. Am J. Med 74: 570-576.
7. Lehrer H. Venkatesh B, Girolamo R, Smith A (1973): Tuberculoma of the brain (revisited) AJR 118 : 594-600.
8. Talamas O, Del Brutto OH; Garcia Ramos G (1989): Brainstem Tuberculoma; an analysis of 11 patients, Arch Neurol.
9. De Angelis LM (1981) Intracranial tuberculoma: Case report and review of literature. Neurology 31: 1133-1136.
10. Wrishber L, Nice C, Karx M (1984) Cerebral computer tomography : a text atlas, Saunders. Philadelphia.
11. Brant-Zawadzki M, Davis PL, Crooks LE (1983) : NMR demonstration of cerebral abnormalities : Comparision with CT AJNR 4 : 120-126.
12. Davidson HD, Steiner RE (1965) MRI in infections on the CNS AJNR 6 : 120-126.
13. Schorth G; Kretzchmar K; Gawehn J, Voigt K (1987): Advantages of MRI in the diagnosis of cerebral infection. Neuroradiology 29: 120-126.
14. Kioumehr, MR Dadsetan, SA Rooholamini, A, AU (1994): Central Nervous System Tuberculosis: MRI. Neuroradiology 36: 93-96.
15. Dastur DK, Lalitha VS: The many facets of neurotuberculosis. An epitome of neuropathology. In Zimmerman RA (ed). Progress in neuropathology Vol. 2 New York. Grune and Stration 1973, 351, 108.
16. Dastur DK, (1983) Neurosurgically relevant aspects and pathognesis of intracranial and intraspinal tuberculomas. Neurosurg Rev. 6 : 103-110.
17. Chang KH, Han MH, Roh JK et al (1990): Gd-DTPA enhanced MR Imaging in intracranial tuberculosis. Neuroradiology 32: 19-25.
18. Gupta RK, Jena A, Sharma A, Guha DK (1988) MR imaging of intracranial tuberculoma, J. computer Assist Tomong. 121: 280-285.
19. Salgado P, Del Brutto OH, Talamas O, Zenteno MA, Rodriguez Carbajal J, Neuroradiology (1989) 31 : 299-302. Intracranial tuberculoma: MR imaging.
20. Dastur HM (1983) Diagnosis and neurosurgical treatment in tuberculous diseases of the CNS. Neurosurgery 6: 11-113.
21. Desai SB, Shah VC, Tavri OJ, Rao P, MRI more specific than CT in cranial tuverculomas. Neuroradiology (1991) : 33 (Suppl).
22. Gupta RK, Pandey B, Khan EM, Mittal P, Gujral RB, Chhabra DK. Intra cranial tuberculomas: MRI signal intensity correlation with histopathology and localized proton spectroscopy. Mag. Res. Imaging (1993), 11: 443-449.

MR Imaging in Multiple Sclerosis: Overview and role of MR imaging: Article by Dr H.S.Das:

Posted by Bobby on

Multiple sclerosis (MS) is an idiopathic inflammatory and most common demyelinating disease of the CNS. Most people with this disease are affected in their prime of their lives, usually between 20 and 40 years of age though exceptions have been documented. Cause of this disease remains unknown. Genetic, viral, autoimmune and environmental factors have been implicated in the disease.

 Pathologic hallmark of MS is multicentric and multiphasic CNS inflammation and remyelination scattered over space and time. In MS, cells of the immune system invade the CNS and destroys the myelin cover leading to demyelination of the axon and damage to the axon itself. In response, other cells of the CNS produce a hard sclerotic lesion (“ the MS plaque”) around the multiple demyelinated sites. Areas of axonal damage can be measured by magnetic resonance spectroscopy (MRS) and is found to correlate with clinical disability. Few lesions in non eloquent areas do not produce clinical symptoms or nerological dysfunction. Such lesions are referred to as “silent lesions”. Approximately 1 per 1000,000 people acquire MS internationally. Throughout adulthood , the female to male ratio is 2:1.

Clinical features:

Sensory problems occur in 20%-50% of patients and are often the earliest symptoms. These manifest as tingling, tight band feeling, crawling sensations etc are found in the extremities and in the trunk and are referred to as paresthesias. Few patients may experience an electric like sensation that goes down the back and legs with head or neck motion (Lhermitte’s sign).

Optic neuritis is the presenting symptom in 15%-20% of patients with MS and usually starts with blurring of vision followed by loss of vision. May appear on one side followed by a later appearance in the other. It rarely involves both eyes simultaneously.

Spasticity occurs due to cortico-spinal tract involvement . Occurs with the initial attack of MS in 30%-40% of patients. It is present in 60% of patients with progressive disease. Usually legs are involved more than the arms.

Other clinical features of MS includes gait and balance incoordination, bladder & bowel dysfunction, fatigue (the single most complaint of people with MS), heat sensitivity, cognitive and emotional dysfunctions etc.

Diagnosis of MS is based on a classic presentation (optic neuritis, transverse myelitis, paresthesias etc) and on the identification of other neurological abnormalities, which is indicated by the patients history and clinical examination. Typical findings in MRI greatly help to establish diagnosis of MS. Patients with atypical presentations and /or a normal or atypical MRI may require evoked potential studies to know about subclinical neurological abnormality. CSF analysis is done to exclude treatable conditions and to document immunological activity in the CNS. Oligoclonal bands are present in over 90% of definite MS, though these can be seen in other inflammatory diseases and in 7% of normal controls. An IgG index of >0.7 is seen in 86%-94% of MS patients and is usually the first CSF abnormality in early MS. 25% patients show elevated protein levels. Presence of myelin basic protein in CSF indicates demyelination though these also can be seen in other neurological conditions like infections, infarct etc. However this protein can be found in the first 2 weeks after a substantial exacerbation in 50%-90% of patients.

Course of disease: The natural course of MS is highly variable and it is impossible to predict the nature, severity or timing of progression in a given patient. Patients with sensory problems tends to have a better prognosis than those with spasticity or paralysis. Another factor that influences prognosis is age of onset. Disease progression tends to be more rapid in patients who experience their first symptoms after age 40. Other factors predictive of rapid progression include male gender, frequent attacks and burden of disease as detected by MRI scans.

Classifications of MS :

Clinically definite MS is further categorized according to disease course. Relapsing-remitting MS (RR-MS) is characterized by symptoms that develop over a period of a few hours to a few days, followed by recovery and a stable course between relapses. Approximately 80% of patients are initially dignosed with relapsing-remitting MS. Almost 50% of patients with relapsing- remitting MS eventually develop secondary-progressive MS (SP-MS) characterized by gradual neurological deterioration with or without superimposed acute relapses. If there is continual disease progression from onset with only minor fluctuation the classification becomes primary-progressive MS (PP-MS). PP-MS occurs in approximately 10 % of patients and mostly who are > 40 years of age. Progressive-relapsing MS (PR-MS), a rare from of the disease, is characterized by gradual neurological deterioration from the onset of symptoms to subsequent relapses.

MR IMAGING IN MS :

MR imaging is the modality of choice in patients with MS . Use of MRI in MS was first described by Young et al in 1981. Previously spin echo ( SE ) sequences like T1, T2 and PD weighted images are commonly used to screen patients with MS. Recently fast or turbo spin echo ( FSE & TSE ) techniques with similar PD and T2 weighted lesion contrast has become popular because this sequences utilize ¼ to 1/3rd of acquisition time. Very small lesions can be missed on FSE sequences because of edge blurring, but taking thinner slices compensates it.

Recent MR developments in imaging of white matter disease :

Nowadays FLAIR ( fluid attenuated inversion recovery ) sequences are widely used because heavily T2 weighted images can be obtained with CSF suppression and enables greater lesion conspicuity in the gray white interface areas. Another technique is EPI ( echo planar imaging ). Use of EPI FLAIR is very useful in detecting early lesions that do not enhance such as Demyelinating disease, acute infarcts and infection.

Diffusion weighted imaging (DWI) :

Normal white matter exhibit anisotropic diffusion with increased diffusion parallel to white matter fibers and restricted diffusion present perpendicular to these fibers. Demylination results in increase in extracellular space which in turn results in increase in water diffusion and diffusion coefficient as compared to normal white matter. Hence in MS, both in acute and chronic plaques there will be increase in diffusion coefficient. Acute plaques has higher diffusion coefficient than chronic plaques probably due to gliosis in chronic plaques. Currently modalities like DTI ( diffusion tensor imaging ) and FA ( fractional anisotropy ) are being utilized for more research in MS.

Quantative magnetisation transfer ( MT ) technique :

Useful in MS patients on drug therapies to know the disease activity. In active plaques there is little demyelination and their MT ratio is slightly reduced which indicates that lesions are most likely to respond to methylprednisolone and more likely to disappear. In contrast chronic plaques have more demyelination and very low MT ratio. These are unlikely to respond to any drug therapy. This technique is now applied to other white matter disease also.

Magnetic resonance spectroscopy (MRS) :

This technique does not produce images but graphs that display levels of metabolites as zones of different colors or shades of gray known as spectroscopic images. In MS tissue metabolite like NAA ( N – acetyl aspartate ) is decreased in chronic plaques and remains normal in active plaques.

MR appearance of MS lesions:

Lesions are typically nodular or ovoid in appearance. Size varies from few mm to more than 1cm. Lesions have propensity to involve the large white matter tracts particularly corpus callosum, medial longitudinal fasciculus and middle cerebellar peduncle. Lesions can also be found in juxtacortical location involving the “U” fibres, along the perimedullary veins at the calloso-septal interface and also in periventricular location giving rise to the classical “Dawson’s fingers appearance”. MS lesions however can involve any portion of the white matter. Recently presence of “ Subcallosal Striations”has been described using sagittal FLAIR sequence. These are thin white lines radiating from the calloso-septal interface and represents the earliest manifestation of MS in this location. Occasionally, MS lesions present as large lesions with mass effect and vasogenic edema indistinguishable from brain tumor by MR imaging ( tumefactive MS plaque). Other nonspecific findings include thinning of the corpus callosum, dirty white matter on T2 weighted images and deposition of non haem iron in the basal ganglia with progression of the disease

Spinal MS :

Spinal MS has a predilection for the cervical spinal cord ( 67 % of cases), with preferential eccentric involvement of the dorsal and lateral areas of the spinal cord abutting the subarachnoid space around the cord. About 55 to 75 % of patients with MS have spinal lesions at some point of time during the course of the disease. As many as 20% of spinal MS lesions are isolated. Spinal lesions enhance after contrast administration. Enhancement may last for 2 to 8 weeks. Steroids do not suppress enhancement of active plaques. Chronic plaques do not enhance and often demonstrate focal cord atrophy. Lesions of other etiologies ( eg, viral myelitis, ADEM ) may resemble MS plaques and must be considered along with the clinical history and the patients sign and symptoms.


 

 


Legends for photos:

Fig1: T2 sagittal image showing Cord change in MS

Fig2. FLAIR coronal image showing plaques (bright lesions) in the supra & infratentorial compartments of brain. Notice the upper cervical cord lesion.

Fig3:. T2 weighted axial image showing multiple Demyelinating plaques (bright lesions) in bilateral periventricular areas.

Typical MR morphology of MS lesion:

Initially MS lesions are isointense to mildly hypointense (black) on T1 weighted images. With time, the hypointensity progresses to develop the so called “T1 black hole”. Some lesions show slight peripheral hyperintensity surrounding the lesion due to presence of free radicles in the surrounding inflammatory tissues. On T2 and PD weighted images the lesions are usually hyperintense (bright).

Role of contrast administration in MS :

In MS contrast enhanced MRI plays an important role depending on the clinical context. Contrast enhancement in general indicates the presence of active inflammatory process. Non enhancing lesions are thought to be chronic lesions. Presence of enhancing and non enhancing lesions is strong evidence to indicate that these multiple lesions are separated in time supporting diagnosis of MS. Presence of ring enhancement suggest reactivation of an old lesion, the central nonenhancing portion representing the “burnt out” portion of the lesion. An incomplete or open ring enhancement is more indicative of an MS lesion.

MR imaging criteria for clinical progression to MS in patients with clinically isolated syndromes ( CIS). MS typically presents as an acute reversible episode of neurologic dysfunction.

Paty et al ( 1988 ) : 4 lesions ( Paty A)

  • : 3 or more lesions, including 1 periventricular lesion ( Paty B)

  • Sensitivity 86 %, Specificity 54 %

Fazekas et al (1988) : 3 lesions with 2 of the following properties.

  • : 5 or > 5 mm diameter of lesion.

  • : Infratentorial or periventricular location.

  • : Sensitivity 86 %, Specificity 54 %

Barkhof et al ( 19 97 ) : 4 lesions criteria

  • : 1 or > 1 Juxtacortical lesion.

  • : 1 or > 1 enhancing lesion or > 9 nonenhancing lesion.

  • : 1 or > 1 infratentorial lesion.

  • : 3 or > 3 periventricular lesions. ( Sensitivity and specificity 73% )

Proposed new diagnostic category : MR imaging supported definite multiple sclerosis ( MRISDMS)

At least one MS –like clinical episode with appropriate clinical findings, remission not necessary.

Abnormal MR image findings ( strongly suggestive of MS).

  • Four or more white matter lesions ( > 3 mm diameter ).

  • 3 lesions with at least one located in periventricular location.

  • One or more of the following specific features.

  • Involvement of corpus callosum.

  • Infratentorial location.

  • Oval shape.

  • > 6 mm in diameter.

  • Some but not all enhancing.

Variants of MS –

Balo’s concentric sclerosis :- Rare, affects young adults, last for few months, concentric bands of intact myelin and demyelinated zones, responds to steroid.

Devic’s disease :- ( neuromyelitis optica) Spinal cord and optic nerves affected. Brain spared . Brain MRI normal. MRI spine shows striking lesions.

Marburg’s disease :- Acute form of MS. Fulminant and progressive.

Schilder’s disease :- Rare, affect children, visual problems and cortical blindness, Seizures, headache, vomiting, large bilateral hemispheres demyelination.

Monophasic syndromes :- Optic neuritis, acute transverse myelitis, ADEM

 

 

 

 

IMAGING IN CEREBRAL VASCULAR PATHOLOGIES:

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IMAGING IN CEREBRAL VASCULAR PATHOLOGIES:

 

EVOLUTION OF INTRACRANIAL HEMATOMA

 

1. Immediate


- liquid with 95% O2 saturated Hb, T2 hyper, T1 iso within seconds platelets thrombi form & cells aggregate

 2. Hyper acute stage -

4-6 hrs, fluid serum begins to disperse

Protein clot retracts, red cells become spherical, oxy

Early peripheral edema begins, T2 iso, T1 iso

OxyHb is diamagnetic with no unpaired electrons,

CT – isodense for 1-3hrs, then becomes dense, 60-100HU
3. Acute stage

- 7-72 hrs, red cells begin to compact, deoxyhb

Central portion T2 hypo, T1 iso

DeoxyHb is paramagnetic with 4 unpaired electrons, T2 shortening

Sheilded from H2O by globin, prevents T1 shortening

No proton-electron relaxation enhancement can occur

Edema pronounced in periphery

Dense on CT, window width of 150-250 best

 

4. Subacute stage -

1-4 wks, methemoglobin starts day 4

Begins at periphery & progresses towards anoxic center

Cells begin to lyse at 1 week releasing metHb, decrease in edema

Perivascular inflammatory reaction begins with macrophage at periphery

Ring Enhancement caused by this process

T1 BRIGHT due to 5 unpaired electrons exposed by globin change

Proton-electron relaxation enhancement does occur

Periphery affected 1st, middle remains iso initially

T2 HYPO early when methemoglobin still in RBC

BRIGHT once the cell breaks down & Hb diluted in water

CT attenuation decreases approx 1.5HU per day

CT is NOT an accurate indicator of age, due to variable Hb etc

 

5. Early Chronic stage

- >4wks, edema & inflammatory reaction subside

Vascular proliferation encroaches on haematoma decreasing its size

Dilute uniform pool of extracellular metHb with vascular walls

Macrophage contain ferritin & hemosiderin at periphery

T2 hypo due to strong magnetic susceptibility

T1 iso due to fact that hemosiderin is water insoluble

Hypodense on CT unless rebleeding has occurred

6. Late Chronic stage -

cystic or collapsed with dense capsule

Vascular proliferation gradually forms fibrotic matrix with macrophage

Infants may resolve completely

Ferritin laden scar persists for years in adults

10% calc with residual hypodense focus in 40%

Gradient echo is helpful in detecting Haem in low field MRI’s

OVERVIEW OF HEMORRHAGE CAUSES

Underlying cause often hidden by the bleed. Intraventricular extension associated with 10% mortality

 

1. Neonatal Hemorrhage – germinal matrix hemorrhage secondary to prematurity

thin walled, proliferating vessels in subependyma of lateral caudothalamic groove

involution occurs at 34 wks when all cells have migrated

No hemorrhage in utero or beyond first 28 days post birth

 

Grade I – Hemorrhage confined to germinal matrix, can be bilateral

Grade II – rupture into normal size ventricles

Grade III – intraventricular hemorrhage with Hydrocephalus

Grade IV – extension to adjacent hemispheric white matter

Can be seen by US in acute & subacute, lucent if chronic

 

Term Infants – Hemorrhage usually secondary to trauma, subdural mostly

Asphyxia & infarction most commonly in non-traumatic cases

Posterolateral lentiform nuclei & ventral thalamus most susceptible

 

2. Hypertension – Most common cause of nontraumatic bleed in adult

Lenticulostriate & Pontine vasculatures mostly involved, penetrating branches of MCA

Usually spontaneous in elderly patients, basal ganglia mostly

Vessels often abnormal, ruptured microanuerysms etc

50% have hemorrhage dissection into ventricles, poor prognosis

Lobar white matter hemorrhage in 20%, cerebellum 10%, midbrain & brainstem rare

Originates along perforating branches near dentate nuclei

Active bleeding usually lasts <1hr

Edema progresses for 24-48hrs, 25% die in this period

Hypertensive Encephalopathy – occurs secondary to elevated BP

Toxemia (Most common) – autoregulation overwhelmed especially in posterior aspect

Overdistention of arteriole leads to BBB breakdown

Reversible vasogenic edema results, frank hemorrhage rare

Cortical petechia & subcortical hemorrhage possible, especially in occipital regions

Increased T2 in external capsule & basal ganglia more common

Chronic renal Diseases, TTP, & Hemolytic-Uremic syndrome other causes

 

3. Hemorrhagic Infarction

Arterial Infarction – hemorrhage when endothelium reperfused

Occurs in 50%, but only seen in 10%, sensitivity: MRI>CT

Cortex & basal ganglia from MCA distribution most commonly, 24-48hrs later

Pseudolaminar Cortical Necrosis – generalized hypoxia

Middle layers usually effected, gyriform hemorrhage

Nonhemorrhagic ischemic changes can occur, gyri calcification possible

Venous Infarction – usually associated with dural sinus thrombosis

Dura around sinus will enhance, clot stays hypodense (empty delta sign)

More likely to effect white matter than cortex

4. Aneurysms – 90% of nontraumatic subarachnoid hemorrhage

Headache common presenting sign for aneurysm, CT best for acute SAH

Blood usually fills ambient cisterns & sylvian first

90% of blood cleared from CSF in 1wk

MRI better for subacute or chronic SAH, dirty CSF

Superficial siderosis – hemosiderin deposit on meninges

Cerebellum brainstem & cranial nerves also coated – neurological dysfunction

Giant aneurysms >2.5cm often have intramural hemorrhage

most from carotid, cavernous portion most common, all ages

75% have calc if thrombosed, none otherwise

Charcot-Bushard Aneurysm – secondary to HTN

5. Vascular Malformations -

AVM & Cavernous Angioma commonly

Most bleed into parenchyma rather than subarachnoid space

Arteriovenous Malformation – pial, dural or mixed, No cap bed

Pial AVM’s – hemorrhage @ 2% per year, often in previously normal young pts

70% bleed by 1st exam, repeated hemorrhage can simulate neoplasm

Central nidus with gliosis & encephalomalacia

Dural AVM’s – no central nidus, SAH or subdural

hemorrhage rare unless drainage through cortical veins

 

Cavernous Angioma – bleed @ .5% per year, freq repeated bleeds

Popcorn like with mixed signal foci & hemosiderin ring

Venous Angiomas – bleed rare, similar hematoma of other malformations

Medusa like collection of dilated medullary veins

Capillary Telangiectasias – usually small & clinically silent

may see multiple small foci of hemosiderin on T2

INTRACRANIAL ANEURYSMS & VASCULAR MALFORMATIONS

Charcot-Bushard Aneurysm – secondary to Hypertension

20% multiple, higher incidence in females.

Look for familial causes such as Polycystic Kid Disease

 

SACCULAR ANEURYSMS

Berrylike out pouching from arterial bifurcation

Include intima & adventitia, media ends with normal vessel

1. Etiology – hemodynamic induced injury, abnormal shear forces most commonly

Trauma, infection, tumor, drug abuse & AV malformations

Berry Aneurysms – associated with polycystic kidney Diseases & aortic coarctation

2. Incidence – 1% of angios & 5% of postmortems

Multiple in 20%, esp in females & polycystic kidney Diseases

Bilateral in 20%, esp at cavernous sinus, Pcom & MCA trifurcation

Occur age 40-60 unless traumatic or mycotic,

 

3. Associated Conditions – occur at anomalous vessels & AVM

Inc pressure ie HTN & aortic coarctation

Systemic Diseases – Marfan’s, fibromuscular dysplasia, polycystic kidney diaeases

 

4. Location – 30% at anterior communicating, 30% at posterior communicating, 20% MCA origin

10% in post circulation especially basilar artery bifurcation

traumatic or mycotic occur anywhere

5. Clinical Presentation – asymptomatic until rupture or giant >2.5cm

1-2% risk of rupture per year, 3.5% risk of surg

No different risk with HTN, age, sex or multiplicity

All should be repaired if >3yr life expectancy

Subarachnoid Hem – clinical grade by Hunt & Hess scale I-V

Vasospasm most common cause of morbidity, 30% die

highest bleed rate in 1st 24hrs, 50% rebleed in 2wk

CT – shows SAH in >80% of ruptured aneurysms

Cavernous sinus aneurysms can compress Nerves III-VI

TIA, Seizures & embolic ischaemia less common

 

Giant Aneurysms – most from supraclinoid carotid, all ages

Fibrous vascular walls, rarely rupture, Symptoms secondary to mass effect

Partially Thrombosed Aneurysms – 75% have curvilinear calcification

CT most specific for these with target seen

NO calc if not thrombosed

D/D – Meningioma, both erode sella & lat sphenoid

aneurysm has no associated hyperostosis or atherosclerosis

 

6. Appearance of Saccular Type – catheter angiography definitive

asses for relation to vessel, adjacent branches & vasospasm

essential in assessment of nontraumatic SAH

Thrombosed aneurysm will have no finding, 15%

may see mass effect if large

irregularity or local vasospasm can indicate rupture

D/D vascular loops & infundibuli (embryonic funnel <2mm)

CT may show bone erosion in long standing case

Patent aneurysms enhance intensely w contrast

Location of SAH can be prognostic indicator

Ambient cisterns anterior to brainstem probably just venous rupture

No repeat angio needed

Suprasellar cistern to lateral sylvian fissure

more aneurysmal pattern, must do F/U angio

MRI dependent on pattern of flow, turbulence & clot

may have wall enhancement with gadodiamide, laminated with thrombosis

 

7. Traumatic Aneurysm -

nonpenetrating usually occur at skull base, or shear

hyperextention stretches ICA over lat C1

 

8. Mycotic Aneurysms – Secondary to infection of arterial wall, rare <10%

adventitia & muscularis disrupted, thoracic aorta commonly

Angio – occur dist to usual location, 2nd branch MCA commonly

most common cause of multiple MCA aneurysms

usually small, staph & strep most common, inc in child

bleed into parenchyma or SAH equal incidence

Medical Treatment usually sufficient to control, surgery if enlarge on angio

Mucor & Aspergilla invade direct from nasopharynx cause thrombosis & infarct more often than aneurysm

 

9. Oncotic Aneurysms – usually extra cranial, exsanguinate freq

tumor may implant or cause emboli, primary or metastatic

 

10. Flow-Related Aneurysms – seen with AVM’s in 30%

distal ones most likely to hemorrhage

 

11. Vasculopathies – rare but seen with SLE, infarct & TIA commonly

Takayasu’s Arteritis – 9:1 female, inflammation & stenosis most commonly

prox arch vessels, L subclavian commonly, often occludes

Fibromuscular Dysplasia – up to 50%, dissection & A-V fistula, 65% bilateral

Cocaine – 50% with CNS symptoms have SAH, may be secondary to HTN treatment

several drugs cause vasculitis .

 

FUSIFORM ANUERYSMS

Etiology – atherosclerosis, exaggerated arterial ectasia

media damaged, stretches & elongates, frequent mural thrombus

Vertebrobasilar Dolichoectasia – Common site, older patient

often thrombus producing brainstem infarcts

can also compress local stem causing nerve palsies

Imaging – enhances if patent, hyperintense if thrombosed

curvilinear calcification pathognomonic, may cause skull base erosion

 

DISSECTING ANEURYSMS

Etiology – intramural blood from tear in intima

may narrow or occlude lumen, may distend subadventitia

do not confuse with Pseudoaneurysm, a encapsulated hematoma

Presentation – usually extracranial unless severe trauma

Commonly in midcervical ICA & vertebral from C2 to skull base

Catheter angio remains procedure of choice for assesment

 

INTRACRANIAL VASCULAR MALFORMATIONS

1. Parenchymal AVM – congenital, dilated arteries & veins without capillary bed

98% solitary, multiple in Osler-Weber-Rendu & Wyburn-Mason

Incidence – 85% supratentorial, peak 20-40y, 25% children

Hemorrhage in 85% with 3% per year risk, seizure 25%, deficit 25%

Size not predictive, deeper & smaller ones bleed more

Parenchymal commonly, also common cause of SAH if

Vascular Steal – atrophy due to vasculopathy of feeding vessel

atrophic low density regions & hematoma with high density

Overlying meninges thick & hemosiderin stained

Angio – shows feeding arteries & tortuous veins

often wedge shaped, possible to appear Normal if thrombosed

GBM may simulate but usually has tissue between vessels

10% have aneurysms in feeding arteries, can bleed

 

Cryptic AVM’s – not seen by angio, 10%

CT – often absent w/o contrast, 25% have mild curvilinear calcification

mixed increased & decreased density if seen, Mild mass effect possible

Enlarged post venous sinuses but not cavernous sinus

Calcification seen in

MRI – honeycomb of flow voids, increased signal if thrombosed

hemorrhage in different stages often present

No significant intervening brain tissue, D/D : GBM

TX – resection if unruptured, must be completely removed

Aneurysms must be treated separately, increased risk for bleed

 

2. Dural AVM’s & Fistulae – form within a venous sinus

no discrete nidus, multiple microfistulae, occluding sinus frequent

Follow recanulation of thrombosed sinus, 10% of all AVM’s

Transverse or Sigmoid sinus commonly, Bruits & headache most common

Cavernous sinus AVM – proptosis, retro orbital pain, proptosis

SAH common if reflux flow forced into cortical veins

Carotid-Cavernous fistula related, follow trauma

Occipital & Meningeal branch of ext carotid #1 feeders

CT often N, MRI may show dilated cortical veins

 

3. Mixed - 15%, if parenchymal AVM recruits arteries from dural supply

 

4. Capillary Telangiectasias – multiple nests of dilated capillaries

Common in pons & Cerebellum, usually incidental

Gliosis of adjacent brain & hemosiderin staining from hem possibly

Cavernous Angiomas assoc or simply the extreme form

Osler-Weber-Rendu – hereditary hemorrhagic Telangiectasias

25% have brain abnormalities, most are true AVM’s

Visceral angio dysplasia with scalp & mucous membrane telangiectasia

2nd most common lesion to venous angioma at autopsy

Not visualized by angio, may present with epistaxis

CT may faintly enhance, faint on MRI

5. Cavernous Angiomas – Hemangioma or cavernoma

Circumscribed nodule of honeycomb sinusoidal vascular spaces

separated by fibrous bands but no intervening neural tissue

frequently MULTIPLE HEMATOMAS at different stages, reticulated core of vessels

Supratentorial 80% but can occur anywhere, 50% multiple

Most Common vascular lesion identified, 20-40y/o

Seizure, deficits & bleed most common presenting features

Angio does NOT visualize, possible faint blush in early venous

CT shows freq Calc, variable enhancement, can simulate neoplasm

MRI – popcorn like appearance on T2 due to multiple hem

multiple areas of signal drop-out due to hemosiderin

VENOUS MALFORMATIONS

1. Venous Angioma – dilated anomalous veins converge on central vein

Etiology – remnant embryonic venous system, usually solitary

assoc with migrational abnormalities & cavernous Angiomas in 30%

Asymptomatic, Hemorrhage very rare unless from associated cavernous angioma

CT – may show linear tuft of vessels post contrast

located in deep White Matter of cortex or Cerebellum, commonly adjacent to frontal horn

MRI – shows stellate tributary veins into prominent collector vein

gliosis or hemorrhage seen in only 15%

Angio – the only vascular malformation with a single draining vein

Medusa head appearance on venous phase of angio

 

2. Vein of Galen Aneurysm – enlargement of Galenic system

Secondary to arteriovenous fistulae from choroidal arteries

AVM in thalmus or midbrain can also cause this

Present at birth with high-out put cardiac failure, cranial bruit +

Macrocephaly with obstructive hydrocephalus, deficits & ocular symptoms

US shows bi-directional flow in vein of Galen

Angio demonstrates either choroidal artery or thalmoperforating feeder

dilation to venous varix with or without distal stenosis

if stenosed distally will often thrombose

CT – large enhancing midline mass posterior to 3rd ventricle

Hydrocephalus frequent but hemorrhage rare

enhancing serpentine vessels in thalamic region

3. Venous varix – assoc with several intracranial vascular abnormalities

Enlarged & thin veins resulting in SAH, hydrocephalus & increased ICP

Sinus Pericranii – venous haemangioma adherent to outer skull, deep to galea

supplied from intracranial sinus & blood returns to sinus

present with enlarging fluctuant soft tissue mass, enlarge with crying

often secondary to trauma, often resolved with prolonged compression

Frontal commonly, parietal next, most near sagittal sinus, can be very lateral

Skull Film – usually sharp margins, vascular honeycombs possible

CT – shows strong uniform enhancement

MRI – well delineated ovoid or fusiform areas variable signal

Venous Cavernoma – subcutaneous lesions of scalp

blood supply from external carotid, drain to external jugular

 

4. Orbital Venous Varix – rare vascular malformation in orbit

Causes intermittent proptosis & diplopia with valsalva & bending over

Disappear completely with axial views, use tourniquet on jugular vein

 

NEONATAL HEMORRAGE

Caudothalamic groove – between head of caudate & thalamus

both make up lateral wall of lateral ventricle, terminates in Monroe

Foramen of Monroe – divides frontal & body portions of ventricles

thalmus entirely posterior, caudate head anterior, choroid enters it

 

1. Subependymal Hemorrhage – preterm infants <32wks

Correlates with size of germinal matrix at birth, largest 24-32wks

involutes & is absent by 40wks, last in inferior lateral wall of frontal

lies inferior to ependyma, superior to head of caudate & anterior to thalmus

Usually occurs in first 3 days, always by 7-8 days

 

Grade 0 – Normal

Grade I – Subependymal alone

Grade II – intraventricular with no ventriculomegaly

Grade III – Hydrocephalus,

Grade IV – intraparenchymal

grade does not predict ultimate outcome, may progress

Serial studies required, only applies to germinal matrix hemorrhage

 

2. Parenchymal Hemorrhage – extends farther lateral than germinal matrix

can be “grade IV”, but not all secondary to germinal matrix bleed

most extend from SHE (Subependymal haemorrhage) to frontal or parietal lobes

Hypoxia & Hypercapnia implicated as etiology

stress causes vessels to dilate & burst

Phase 1 – echogenic like SEH for 1-2wks

Phase 2 – central Hypoechoic, bright peripheral rim 2-4wks

Phase 3 – retracts & settles into dependent position

Phase 4 – necrosis & phagocytosis complete, encephalomalacia

Cerebellar hematoma best scaned in coronal behind ear

assoc with mortality of 50%.

 

3. Choroidal Hemorrhage – usually grade II or III

Second cause of intraventricular hemorrhage not caused by SEH

Difficult to discern from normal choroid on US

asym scanning can show marked asym in choroid size

isolated choroid hematoma simulates ventricular hematoma with no hydrocephalus

Myelomeningocele assoc with pedunculated choroid

CT more reliable than US for Dx

D/D – Choroid Papilloma, very rare, consider if CSF clear on tap

all assoc with hydrocephalus, enhance intensely on CT

HEMORRHAGIC NEOPLASMS & CYSTS

 

1. Malignancy Related Coagulopathy – esp with leukemia & chemotherapy

systemic neoplasms can be assoc with term coagulopathy

 

2. Intratumoral Hematomas – 10%, malignant , Astrocytoma’s are most common.

Neovascularity, central necrosis, plasminogen activators etc contribute

Heterogeneous, incomplete hemosiderin ring, edema persist

multiple lesions & min edema suggests nonneoplastic cause

Cysts & slow growing cystic neoplasm like cranio rarely bleed

Oligodendroglioma, neuroectodermal & teratoma hemorrhage frequently

Ependymoma & choroid tumors – frequent SAH & hemosiderosis

Pituitary Adenoma – may bleed more frequently than astrocytoma

Lymphoma rarely bleed unless with AIDS

Renal cell Ca, chorio Ca, melanoma, thyroid & lung mets, 15%

 

3. Nonneoplastic Hemorrhagic Cysts -rare, colloid cysts never bleed

Rathke cleft cysts & Arachnoid cysts more commonly bleed

Arachnoid cysts bleed secondary to trauma, bridging vessels rupture

sometimes assoc with subdural hematoma

MISCELLANEOUS CAUSES OF BENIGN INTRACRANIAL HEMORRHAGE

1. Amyloid Angiopathy – Most common cause of bleed in elderly patient with no HTN

nonbranching fibrillar protiens form beta-pleated sheets

Deposit is Cortical & leptomeningeal vessels

extend from small vessels to brain parenchyma

Contractile elements replaced by the crystals

Multiple hematomas frequent & occurs at cortico medullary junction

basal ganglia & brainstem not affected

2. Infection & vasculitis – rare, increased chance if immuncompromised

septic emboli – mycotic aneurysms & hemorrhagic infarct

10% of Infective endocarditis have SAH or parenchymal

Aspergillosis & other fungi directly invade vessel

Thrombosis, infarction & hem result

Herpes Simplex II – the only encephalitis assoc with hematoma

 

3. Recreational Drugs – 50% have preexisting AVM or aneurysm

Cocaine can induce an acute hypertensive episode, vasospasm

also enhances platelet aggregation, dural sinus thrombosis

amphetamine & PCP also associated with hemorrhage

endothelial damage & necrotizing vasculitis

 

4. Blood Dyscrasias & Coagulopathies – iatrogenic or acquired

Vit K deficiency, hepatocellular diseases, antibody against clot, DIC

Anticoagulants, thrombolytics, aspirin, Etoh abuse, chemo

15% of all intracranial hemorrhage on anticoagulants

Supratentorial, intraparenchymal bleeds most common

 

 

 

CT & MRI IMAGING IN CNS TUBERCULOSIS:

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CT & MRI IMAGING IN CNS TUBERCULOSIS:

AUTHORS: Dr Himadri Sikhor Das, Dr P.Hatimota, Dr P.Hazarika, Dr C.D.Choudhury.
INSTITUITION: MATRIX, Guwahati -5, Assam, India.
ADD FOR CORRESPONDENCE: MATRIX, Guwahati -5, Assam, India.
drhsdas@gmail.com

ABSTRACT: Tuberculosis (TB) of the central nervous system (CNS) is a granulomatous infection caused by Mycobacterium tuberculosis. Infection is by haematogenous spread from a primary focus, usually the lung. Infection starts in subpial or subependymal cortical focus (ie, Rich focus), resulting in a granuloma that erodes into the subarachnoid space causing basal leptomeningitis. The meningitis usually causes communicating hydrocephalus, but it may also cause obstruction of the foramina of Luschka and Magendie, resulting in obstructive hydrocephalus. Vasculitis involving the lenticulostriate and thalamoperforatoring arteries may occur and cause small infarcts in the deep gray nuclei and deep white matter. Other manifestations of tuberculosis are focal parenchymal granulomas (eg, tuberculomas), tuberculous abscesses, tuberculous cerebritis, and pachymeningitis. In addition, spinal cord infection is less common, but it results in either arachnoiditis, spondylodiskitis (Pott’s spine) or uncommonly, focal intramedullary tuberculomas. Clinical diagnosis can be difficult; therefore, imaging has an important role in establishing the diagnosis. The imaging spectrum of CNS tuberculosis along with few atypical cases are presented in our paper.

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osteoid osteoma

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Osteoid osteoma is a benign lesion that accounts for approximately 10% of benign bone tumors. It occurs predominantly in children and young adults between 10 and 25, affecting males twice as often as females. The clinical presentation typically consists of pain, which is often worst at night, increased skin temperature, sweating, and tenderness in the affected region. Pain is completely relieved by salicylates in many cases.
Predilection sites are proximal femur, and diaphysis of long bones, which account for more than half of all cases, and less often foot and the posterior elements of the spine (1). Osteoid osteomas are usually detected on radiographs, typically showing a radiolucent nidus surrounded by sclerosis in the cortex of the bone. If an osteoid osteoma is suspected and radiographs are negative, skeletal scintigraphy is especially useful with a sensitivity of 100% (2). Radionuclide angiography and tissue-phase imaging often, but not always, show prominent tracer delivery and early localization. On skeletal-phase images a well-localized, focal tracer uptake is typically noted (3). Characteristic is a cloud of diffuse increase of radiotracer around the prominent focus, which is better seen on images obtained with pinhole magnification technique (4). In complicated cases computed tomography might be helpful to visualize the nidus. Scintigraphy also is contributory for treatment of patients with osteoid osteoma by ensuring complete removal of the lesion. This can be achieved either by imaging the specimen that should demonstrate a normal margin of bone around the lesion or intraoperatively with a mobile gamma camera, demonstrating that no residual activity suggestive of osteoid osteoma tissue is left (5).

D/D: Osteomyelitis

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Hypoxic Ischaemic Encephalopathy HIE

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GI differential Diagnoses

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GI differential Diagnoses

ESOPHAGUS
Diverticular disease: pharyngocele, Zenker, Killian Jamieson, traction, pulsion, pseudodiverticula, epiphrenic
Luminal narrowing: webs, Plummer-Vinson, vascular ring, Schatzki ring, strictures (reflux, meds, skin lesions, tumor, mets, radiation, eosinophilic gastroenteritis, Crohn’s, lye, Barrett’s, infection, NGT, achalasia, scleroderma, Chagas), extrinsic compression (aorta, left bronchus, left atrium, mediastinal tumor)
High stricture: Barrett’s, radiation, caustic ingestion, CA, mets, meds, skin dz, Crohn’s
Low stricture: peptic stricture, lower esophageal ring, Barrett’s
Nodules/plaques: diffuse – reflux, Candida, glycogenic acanthosis; localized – Candida, superficial spreading CA, Barrett’s

Ulcers: distal – reflux, Crohn’s; small, mid – herpes, medications (tetracycline, doxycycline, KCl, iron, quinidine, NSAIDs, vit C, Fosamax), Crohn’s; giant – CMV, HIV

Megaesophagus: achalasia, scleroderma, distal narrowing from tumor or stricture, Chagas

Contrast extravasation: esophagitis, tumor, vomiting (MW tear, Boerhaave), TE fistula, foregut duplication cyst with communication to esophagus, iatrogenic, trauma

Solitary filling defects: intraluminal – food impaction, foreign body, fibrovascular polyp, spindle cell tumor, leiomyosarcoma, adenocarcinoma; tumor – leiomyoma, fibrovascular polyp, duplication cyst, papilloma, fibroma, hemangioma, SCC, adenocarcinoma, spindle cell tumor, lymphoma, mets (breast, lung, KS, melanoma, RCC); varices – uphill (portal HTN), downhill (SVC obstruction); extrinsic – lymph nodes, engorged vessels, aneurysms, cysts

Thickened folds: esophagitis, lymphoma, varicoid carcinoma, varices
Air-fluid level: hiatal hernia, esophageal diverticulum, CA, achalasia, scleroderma
Feline esophagus: reflux, motor disorders
Corkscrew esophagus: diffuse esophageal spasm, presbyesophagus

STOMACH
Gastritis: H pylori, erosive gastritis (corrosives, alcohol, stress, NSAIDS), granulomatous (Crohn’s, sarcoid, TB, histo, syphilis), eosinophilic, hypertrophic (Menetrier’s, ZE syndrome), recurrent gastric ulcer (ZE syndrome, PUD, drugs), radiation, emphysematous
Target lesions: gastritis (aphthoid type) – erosive (NSAID, alcohol), Crohn’s, infection (Candida, herpes, CMV); submucosal mets (large ulcer) – melanoma, KS > breast, lung, lymphoma; solitary giant bullseye (very large ulcer) – leiomyoma, sarcoma, CA, solitary met, ectopic pancreas, benign ulcer

Filling defect: bezoar, adenocarcinoma, lymphoma, leiomyosarcoma, mets, KS, endometriosis, carcinoid, leiomyoma, lipoma, polyps (hyperplastic #1), varices, ectopic pancreas, extrinsic compression from spleen/pancreas/liver
Giant rugal folds: lymphoma, Menetrier’s, ZE syndrome, gastritis, eosinophilic gastroenteritis, radiation, infection, Crohn’s, mets, varices (mimic)

Linitis plastica: scirrhous CA (#1), lymphoma, mets (esp breast), pancreatic CA (direct invasion), radiation, Crohn’s, eosinophilic gastroenteritis, corrosive ingestion, TB, sarcoid, syphilis

Antral lesions: adenocarcinoma, lymphoma, mets, Crohn’s, PUD, TB, sarcoid, HPS, pylorospasm, antral web, ectopic pancreas, erosive gastritis, caustics

Double pylorus: lesser curve antral ulcer, Crohn’s, lymphoma

Gastroenteric fistula: PUD, Crohn’s, CA, iatrogenic, surgery
Free air: surgery and laparoscopy, perforated ulcer, perforated distal bowel (IBD, diverticulitis, tumor)

UGI surgery: plication defect, marginal ulcer, bezoar, chronic gastritis, leak, obstruction, intussusception (jejunogastric), gastric CA, afferent loop syndrome, malabsorption

DUODENUM
Filling defects: benign (often 1st portion, asx) – adenoma, leiomyoma, lipoma, villous adenoma, ectopic pancreas; malignant (often distal to 1st portion, sx) – adenocarcinoma at or distal to papilla, leiomyosarcoma, lymphoma, mets (melanoma, breast, KS, carcinoid); bulb – ectopic gastric mucosa, prolapsed antral mucosa, Brunner gland hyperplasia, varices, duodenitis, Crohn’s, lymphoma, sprue, CF, polyposis, benign tumors; distal – benign lymphoid hyperplasia, ectopic pancreas, annular pancreas, ampulla of Vater, tumor, edema with impacted or passed gallstone, choledochocele; soft and changing – choledochocele, lipoma, duplication cyst

Target lesion: leiomyoma, leiomyosarcoma, met (melanoma, KS, breast, lung, lymphoma), ulcer, ZE syndrome

Luminal outpouchings: ulcer, diverticulum, choledochoduodenal or cholecystoduodenal fistula
Reverse figure 3 sign: pancreatitis, pancreatic CA
Notched duodenum: annular pancreas, post-bulbar ulcer, Crohn’s, post-op, pancreatitis, pancreatic CA

Postbulbar narrowing: adenocarcinoma, lymphoma, mets, postbulbar ulcer, duodenitis, Crohn’s, pancreatitis (extrinsic), pancreatic CA, annular pancreas, intramural diverticulum, duodenal duplication cyst, duodenal hematoma, aortic aneurysm, SMA syndrome (seen in scleroderma, lymphoma)

Papillary enlargement: >15mm; normal variant, choledochocele, papillary edema (pancreatitis, acute duodenal ulcer, impacted stone), ampullary CA

JEJUNUM AND ILEUM

Adynamic ileus: postoperative (#1); inflammatory (often sentinel loop) – pancreatitis, appendicitis, cholecystitis, diverticulitis, peritonitis; metabolic – low K+, Ca++, Mg++; medication – morphine

Mechanical SBO: adhesion, hernia, tumor, gallstone, inflammation with strictures
alabsorpmtion patterns: dilatation, dilution, delay; predominantly thick/irregular folds – Whipple’s, MAI, Strongyloides (proximal), amyloid, Giardia (jejunum), GVH, Cryptosporidium (jejunum), lymphoma, lymphangiectasia, mastocytosis, eosinophilic gastroenteritis; predominantly dilated loops and normal folds – sprue (#1), obstruction, ileus, scleroderma, medication

Thick folds without malabsorption pattern: criteria – folds >3mm, uniformly thickened if diffuse, nodular thickening (pinkyprinting) if focal with stack of coins appearance; submucosal edema – ischemia, infection, radiation, hypoproteinemia, GVH; submucosal tumor – lymphoma, leukemia, submucosal hemorrhage – Henoch-Schonlein purpura, hemophilia, anticoagulation

Tubular bowel: Cryptosporidium, sprue (proximal), lymphoma, GVH, radiation, ischemia, Strongyloides (proximal)

Nodules: mastocytosis, nodular lymphoid hyperplasia, lymphoma, mets, polyps, Crohn’s, eosinophilic gastroenteritis, TB, infection, amyloid, lymphangiectasia, Whipple’s, Waldenstrom’s macroglobulinemia

Diffuse tiny nodules: lymphoid hyperplasia (#1), hypogammaglobulinemia, Giardia, Whipple’s, Waldenstrom’s

Small bowel tumors: benign – adenoma (#1), leiomyoma (#2), lipoma, hemangioma, neurogenic tumors, Brunner gland hyperplasia, heterotopic pancreatic tissue; malignant – mets (melanoma, RCC, breast, KS), lymphoma, carcinoid (#1 primary tumor), leiomyosarcoma (large ulcerating), adenocarcinoma; polyposis syndromes

Small bowel stricture: Crohn’s, lymphoma, mets, infection, radiation, ischemia, adenoCA, extrinsic compression, NSAIDs; focal stricture with shouldering – adenoCA (#1), breast mets, TB

Coiled spring: intussusception, intramural hematoma

Large ulcerated mass (endoexoenteric): lymphoma, leiomyosarcoma, mets (melanoma), interloop abscess

Diverticula: small bowel, Meckel’s

Intraluminal filling defects: parasites (Ascaris, tapeworm), bezoar, foreign body, gallstone, lipoma

Enteric fistulas: Crohn’s, diverticulitis, CA, TB, radiation, surgery, iatrogenic

Serosal: carcinoid, serosal mets, diverticulitis, appendicitis, endometriosis

Mesenteric bowel ischemia: occlusive – emboli (afib, LV aneurysm), arterial thrombosis (atherosclerosis), venous thrombosis (portal HTN, pancreatitis, tumor, hypercoagulable state, drugs); nonocclusive – low flow state

Shortened transit time: anxiety, hyperthyroid, medication (reglan), partial SBO

COLON

Crohn’s: fold thickening, wall thickening, nodular pattern (cobblestone), string sign, aphthoid ulcers, filiform polyps, sinus tracts and fistulas, mesenteric fat stranding, creeping fat, lymphadenopathy, separated bowel loop (omega sign), pseudosacculations, strictures, asymmetric, skip lesions

UC: ahaustral, granular mucosa, filiform polyps, starts in rectum, continuous spread, backwash ileitis, crypt abscesses, strictures (worrisome)

Mass lesions: normal lymphofollicular pattern, pneumatosis coli, colitis cystica profunda, amyloid, endometriosis, ischemic colitis, polyps, polyposis syndromes, lipoma, leiomyoma, hemangioma, villous adenoma, adenocarcinoma, mets, lymphoma, hemorrhoids

Polypoid filling defects: polyps – hyperplastic (#1), adenomatous (#2), hamartomatous, post-inflammatory; polyposis – FAP, Peutz-Jeghers, juvenile polyposis, Turcot, Cronkhite-Canada, Cowden; lymphoma; pneumatosis

Carpet lesion: villous adenoma, adenoCA, polyposis, endometriosis, varices

Colonic urticaria: herpes, Yersinia, allergy, Crohn’s, ischemia

Aphthoid ulcers: Crohn’s, amebiasis, Behcet’s, CMV, herpes, TB, Yersinia (TI)

Deep ulcers: UC, Crohn’s, Behcet’s, infectious (amebiasis, TB, Salmonella, Shigella, histo, Candida, herpes, CMV), ischemic colitis, radiation

Bowel wall thickening (thumbprinting): hemorrhage – ischemia, Henoch-Schonlein purpura, hemophilia, anticoagulation; tumor – lymphoma, leukemia; edema – infectious (pseudomembranous colitis, CMV, E Coli, Salmonella, Shigella, amebiasis, typhlitis), IBD

Circumferential (apple core) or asymmetric narrowing: tumor – adenocarcinoma, serosal mets (stomach, ovarian, colon, pancreas); inflammation – diverticulitis, IBD, TB, amebiasis; other – endometriosis, pelvic abscess, epiploic appendagitis; multifocal – lymphoma, serosal mets, TB, amebiasis, Crohn’s, endometriosis

Long segment narrowing: scirrhous adenocarcinoma, lymphoma, UC, Crohn’s, ischemic stricture, radiation

Ahaustral colon: cathartic abuse (usu R colon), UC, Crohn’s, amebiasis, aging (usu L colon), scleroderma, radiation, prior ischemia

Pseudosacculations: Crohn’s, scleroderma, ischemia

Obstruction: CA, diverticulitis, volvulus, impaction, hernia

Megacolon: toxic megacolon – pseudomembranous colitis, UC, Crohn’s, amebiasis; acute distension – obstructive CA, ileus, volvulus; chronic – laxative abuse, Ogilvie syndrome, congenital Hirschsprung’s, Chagas, neuromuscular disorders (Parkinson, DM, scleroderma, amyloid), hypothyroid

Adult intussusception: usually ileoileal; tumors – polyps, lipoma, mets, lymphoma, carcinoid; idiopathic, Meckel’s diverticulum, feeding tube; no lead point consider sprue, scleroderma, Whipple’s

Pneumatosis coli: pneumatosis cystoides – COPD, asthma, CF, iatrogenic, CVD, steroids; pneumatosis intestinalis – infarcted bowel, NEC, toxic megacolon, typhlitis

Coned cecum: Crohn’s, lymphoma, mets, TB, amebiasis, typhlitis

Ileocecal deformities: Crohn’s, UC, amebiasis (spares TI), TB, typhlitis, lymphoma, adenocarcinoma, carcinoid, intussusception

Enlarged ileocecal valve: >3cm; lipomatous infiltration (#1), lipoma, Crohn’s, lymphoma, prolapsing ileal neoplasms

Cecal filling defect and nonfilling appendix: carcinoid, appendicitis, appendix stump, mucocele

Fat containing mass adjacent to colon: epiploic appendagitis, omental infarction

Proctitis: Condyloma acuminata, lymphogranuloma venereum, GC, UC, Crohn’s, HIV, herpes

Rectal involvement: serosal mets, TOA, radiation, appendicitis, diverticulitis, endometriosis

Presacral space widening: >2cm; rectal inflammation (colitis, radiation), infection, tumor, pelvic lipomatosis, edema hemorrhage

LIVER

Solid masses: hemangioma, FNH, adenoma, HCC, mets, regenerating nodules, focal fatty deposition, lymphoma

Cystic masses: infectious – pyogenic abscess, amebiasis, Echinococcus; benign – simple cysts, ADPKD, biliary cystadenoma, biloma, intrahepatic GB; malignant – necrotic tumors, cystic mets, cholangioCAcreased density: hemochromatosis, glycogen storage disease, Wilson’s, amiodarone, chemotherapy, thorotrast, anemia, regenerative nodules in cirrhosis (low T2)

Decreased density: fatty liver – obesity, alcohol, DM, steroids, chemotherapy; radiation-induced

Mottled density without focal mass: passive congestion, Budd-Chiari, geographic fatty infiltration, hepatoma, lymphoma

Hypervascular: hemangioma, hemangioendothelioma, cholangioCA, HCC, mets (islet cell, melanoma, carcinoid, RCC, thyroid, breast, sarcoma)

Hyperechoic: round – hemangioma, hyperechoic mets (hypervascular and calcified mets), HCC, fibrolamellar HCC, focal fat, lipoma, AML, Gaucher’s; linear – pneumobilia, PV gas, biliary ascariasis; multiple punctate foci – hepatitis, granulomatous infection, PCP, biliary hamartomas, pneumobilia, PV gas, vascular calcs

Multiple hypoechoic: tumor – mets, lymphoma, HCC; infection – pyogenic, amebic, Echinococcus, Candida, Schistosomiasis; other – regenerative nodules in cirrhosis, sarcoid, extramedullary hematopoiesis, hematomas, hemangiomas

Hepatic hemorrhage: iatrogenic, trauma, adenoma, HCC, pregnancy

Gas in liver: pneumobilia – ERCP, surgery, penetrating ulcer, gallstone ileus, CA, bowel obstruction; PV air – bowel necrosis > IBD, abscess, obstruction, ulcer, NEC, iatrogenic, liver transplant; abscess; emphysematous cholecystitis

Delayed retention of contrast: cholangioCA, hemangioma, fibrous tumor, scar (FNH, adenoma, fibrolamellar HCC, hemangioma)

BILIARY SYSTEM

Extrahepatic biliary dilatation: intrapancreatic (#1) – pancreatic CA, calculus, chronic pancreatitis; suprapancreatic – cholangioCA, metastatic lymph nodes; portal – cholangioCA, GB CA, surgical strictures, hepatoma; choledochal cyst

Types of obstruction: tumor – abrupt termination of duct, mass adjacent to duct; pancreatitis -–smooth, long tapering; lithiasis-related – calculus visible, meniscus sign, intrahepatic dilatation; cholangitis – sclerosing, AIDS, oriental; Caroli’s; biliary cystadenoma

Double duct sign: dilated BD and PD; pancreatitis, pancreatic CA, stone impacted in ampulla, cholangioCA, duodenal or ampullary CA

Filling defects in bile duct: stone, blood clot, parasite, sludge, tumor

Hemobilia: iatrogenic, tumor, trauma, infection

Strictures on ERCP: hilum – cholangioCA, porta hepatis nodes, GB CA; 1cm from ampulla – pancreatic CA, cholangioCA, mets; long segment – chronic pancreatitis, lymphoma; CHD at cystic duct region – Mirizzi’s, GB CA, cholangioCA; multiple intrahepatic – sclerosing cholangitis, HIV, ischemic, primary biliary cirrhosis, liver mets (rare); multiple intrahepatic and extrahepatic -–sclerosing cholangitis, HIV, ischemia

Irregular wall and filling defects: cholangitis – HIV, oriental, ascending

Pancreatic duct: stricture – pancreatic CA, chronic pancreatitis; cystic dilatation and side branches – chronic pancreatitis, IPMT; variants – annular pancreas, pancreas divisum

Cholecystectomy leaks: cystic duct remnant, duct of Luschka

GB wall thickening: >3mm; diffuse – nonfasting GB, acute cholecystitis, chronic cholecystitis, portal HTN, hypoalbuminemia, hepatitis, AIDS (cryptosporidium, CMV, MAI), ascites; focal – GB CA, mets (melanoma), cholesterol polyps, adenomyomatosis, tumefactive sludge, AIDS

GB wall hyperechoic foci: calculus, polyp, cholesterol, emphysematous cholecystitis, porcelain GB

Dense gallbladder: vicarious excretion of contrast, calculi, milk of calcium, oral cholecystogram, hemorrhage

Biliary enteric fistula: cholecystitis (gallstone ileus), PUD, tumor, trauma, surgery, Crohn’s

PANCREAS

Focal pancreatic signal abnormality: tumor, focal pancreatitis, adenopathy

Pancreatitis: causes – biliary stones, alcohol, drugs, hyperlipidemia, infection, trauma; complications – fluid collection, pseudocyst, abscess, necrosis, splenic artery pseudoaneurysm, splenic vein thrombosis

Cystic lesions: tumor – microcystic adenoma, mucinous cystadenoma, IPMT, solid/cystic and papillary epithelial neoplasm, cystic islet cell tumor; cyst – simple, pseudocyst, ADPKD, VHL, duct ectasia; abscess

Hyperechoic pancreas: CF, pancreatic lipomatosis

Hypervascular: islet cell tumor, hypervascular mets

Hypovascular: adenocarcinoma, focal chronic pancreatitis

SPLEEN

Anatomic variations: accessory spleen, lobulations, wandering spleen, polyspenia, asplenia, splenosis (s/p trauma)

Focal splenic lesions: tumor – mets (lymphoma, melanoma), hemangioma, lymphangioma, hamartoma; infection (often calcified) – abscess, Candida, TB, MAI, Schistosomiasis, PCP; other – infarct, septic emboli, hematoma, cyst (simple, hydatid) pancreatic pseudocyst, fatty nodules in Gaucher’s

Microabscess pattern: Candida, MAI, TB, PCP, bacterial, fungal, Gaucher’s, sarcoid, KS, lymphoma, mets

Scalloped contour: infarcts, septic emboli, hematoma, metastatic implants, pseudocyst

Splenic cyst: primary – congenital, true; secondary – calcified, false, prior infarct, trauma, infection, echinococcus, pancreatic pseudocyst

Splenic calcifications: TB, histo, PCP, phleboliths, hemangioma

Splenomegaly: tumor – lymphoma, leukemia; infection – infectious mono, histo, sarcoid; metabolic – Gaucher’s, amyloid, hemochromatosis; trauma; vascular – portal HTN, hematologic disorders

PERITONEAL CAVITY

Peritoneal mets: ovarian, stomach, colon, pancreas

Pseudomyxoma peritonei: mucinous cystadenoCA from ovary or appendix, mucocele

Peritoneal fluid collections: ascites, urinoma, biloma, seroma, lymphocele, pseudocyst, CSFoma; complex – abscess, hematoma, pseudomyxoma peritonei, pancreatic necrosis

Intraperitoneal calcifications: arterial calcs, appendicolith, mesenteric node, gallstone, pancreatic calcs, porcelain GB, renal/ureteral stone, nephrocalcinosis, old hematoma, abscess, fibroid, fetal skeletal part, phlebolith, teratoma, echinococcal cyst, mucinous tumor

MISC

General GI DDx: Crohn’s, lymphoma, TB (infection), mets, CA, radiation, ischemia
Mucosal: acute angle, absence of normal mucosal pattern, irregular fuzzy margin

Submucosal: obtuse angle, presence of normal mucosal pattern, smooth distinct margin

Extrinsic: spiculation, tethering

AIDS: infection – CMV, Candida, herpes, Cryptosporidium, MAI; tumor – KS, lymphoma; esophagus – ulcers (Candida, CMV, herpes, HIV), sinus tracts (TB, Actinomycosis); proximal small bowel – ulcers (cryptosporidium), nodules (KS, lymphoma, MAI); distal small bowel – enteritis (TB, MAI, CMV); colon – colitis (CMV, pseudomembranous), typhlitis; rectum – herpes, lymphoma; biliary – strictures (CMV, Cryptosporidium); liver and spleen – KS, lymphoma, Candida, TB, MAI, PCP

Abdominal trauma: liver laceration (#1), splenic lac, renal trauma, bowel hematoma, pancreatic fx, GB injury, adrenal hemorrhage

Abdominal complications after cardiac surgery: GI hemorrhage, cholecystitis, pancreatitis, perforated peptic ulcer, mesenteric ischemia, perforated diverticulitis

Low density lymph nodes: TB, MAI, lymphoma, testicular tumor, mucinous adenoCA, Whipple’s

Cystic abdominal mass: abscess, loculated ascites, panc pseudocyst, ovarian cyst or tumor, lymphocele, cystic lymphangioma, enteric duplication cyst, cystic teratoma

Mesenteric mass: lymphoma, mets, carcinoid, mesenteric fibromatosis, mesothelioma

Large LUQ mass: stomach (leiomyosarcoma), pancreas (pseudocyst, nonfunctioning islet cell tumor, mucinous tumor), adrenal (carcinoma), spleen (lymphoma), kidney (RCC, lymphoma)

RLQ inflammation: appendicitis, Crohn’s, cecal diverticulitis, perforated cecal CA, mesenteric adenitis, PID

Volvulus: gastric (organoaxial, mesenteroaxial), midgut, colon (sigmoid, cecal)

Hernia: paraesophageal, paraduodenal, inguinal, umbilical, Spigelian, lumbar, Richter’s, incisional

Abdominal wall: mets (melanoma, NF, iatrogenic seeding), rectus sheath hematoma (trauma, anticoagulation)

Ascites: cirrhosis, mets, CA, hypoalbuminemia, CHF, pancreatitis

Gasless abdomen: obstruction with fluid-filled bowel, severe vomiting, high obstruction, achalasia, impaired swallowing, continuous NG suction

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PARANASAL SINUS IMAGING WITH SPECIAL REFERENCE TO FUNCTIONAL ENDOSCOPIC SINUS SURGERY (FESS).

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“Functional” endoscopic sinus surgery (FESS) is based on the logic that removing cause of obstruction to normal mucociliary clearance in the area of the Ostiomeatal Unit (OMU) will lead to subsequent clearance of secondary disease and restoration of normal mucociliary clearance. This is in contrast to more extensive interventions in which nearly all accessible mucosa is debrided. Although this is sometimes necessary, as in severe nasal polyposis, such extensive procedures usually are not required and add to the overall risk of complications. Endoscopic sinus surgery is most commonly performed for inflammatory and infectious sinus disease. Endoscopic surgery is planned preoperatively by nasal endoscopy and CT imaging, the gold standard of which is the high resolution CT in coronal plane which accurately images the OMU including its drainage pathways.

Preoperative imaging helps to identify unsuspected old fractures or congenital deformities that distort anatomy and predispose the orbit, optic nerves, and carotid arteries to injury during FESS and acts as a roadmap to the endoscopic surgeon. High-resolution CT scanning with thin coronal slices provides the most useful surgical information because the orientation of the anatomy is similar to the orientation of the anatomy encountered in FESS. Axial images do not show certain ostia as well as the coronal projection but can still provide additional information. Most protocols for CT scanning of the sinuses use a coronal position with slices 2-3 mm in thickness along with axial images. Some institutions use thin-section axial CT images that are reformatted in the coronal projection. Reformatted images in the coronal plane have less spatial resolution in the superior-inferior direction than direct coronal scans. However, these images may be digitized and downloaded to an intraoperative computer for virtual reality display, superimposing them over the direct endoscopic images seen by the surgeon. Dental metallic devices are one of the most significant causes of CT scan degradation. These devices cause considerable streak artifacts that obscure the nasal cavity and sinus anatomy. When streak artifacts degrade direct coronal scans, inversion of black and white may help. Bone is changed from its normal white to black, and air is changed from its normal black to white. Thus, white air channels and spaces are easier to visualize, and streak artifacts have been inverted to black, making them less obvious. Conversion of all sinus scanning to coronal imaging and CT scanning may prevent diagnosis of nasal cavity neoplasms. In the absence of bone destruction, a neoplasm may be mistaken for a nasal polyp, whereas on MRI, the nature of this tumor is quite apparent. Beyond anatomic variants, anything suspicious should be imaged by means of MRI. Despite the advances of MR, insufficient tissue, plus the problems of susceptibility due to the air-containing passages, make MR a less effective study for nasal cavity sinusitis problems, unless of course the sinusitis turns out to be related to squamous cell carcinoma.

Indications : Endoscopic sinus surgery is most commonly performed for inflammatory and infectious sinus
disease. The most common indications for endoscopic sinus surgery are as follows:
Ø Chronic sinusitis refractory to medical treatment
Ø Recurrent sinusitis
Ø Nasal polyposis
Ø Antrochoanal polyps
Ø Sinus mucoceles
Ø Excision of selected tumors
Ø Cerebrospinal fluid (CSF) leak closure
Ø Orbital decompression (eg, Graves ophthalmopathy)
Ø Optic nerve decompression
Ø Dacryocystorhinostomy (DCR)
Ø Choanal atresia repair
Ø Foreign body removal
Ø Epistaxis control

Contraindications of FESS: Certain conditions may require an external approach for complete treatment of disease; these include intraorbital complications of acute sinusitis, such as orbital abscess or frontal osteomyelitis with Potts puffy tumor. An open approach in these instances, with or without additional endoscopic assistance, may be preferable. A careful review of the preoperative CT scans films helps to guide the surgeon.

Relevant Anatomy for the Radiologists: The floor of the nasal cavity is the hard palate. The lateral walls contain spiral-shaped mucosal folds overlying concha-shaped bone called turbinates and various sinus-drainage ostia. The roof is composed of the cribriform plate in the middle with the ethmoid air cells on either side. The nasal cavity is separated into halves by a midline, which is a partially bony and partially cartilaginous nasal septum that, unlike the lateral walls, is lined by squamous epithelium.

Paranasal sinuses: Paired frontal, maxillary, ethmoid, and sphenoid sinuses surround the nasal cavity. Ethmoid sinuses form the roof, and maxillary sinuses form the walls. The major draining ostia are the anterior ostiomeatal complexes or unit (OMC or OMU) which drains the bilateral frontal and maxillary sinuses and the anterior and middle third of the ethmoid sinuses. The uncinate process (UP) and lateral wall of the nasal cavity form the ethmoid infundibulum (EI). The above sinuses drain into the EI via various ostia. The maxillary sinus ostia and the frontal sinus recess or duct drain into the anterior most portion of the OMC and are consistently identifiable on CT scan.

The most common cause for frontal and maxillary sinusitis is anterior ethmoid disease and a superimposed rhinitis, whether viral or bacterial. Clearing or treating anterior ethmoid disease clears frontal and maxillary sinusitis. The inferior turbinate extends along the inferior lateral nasal wall posteriorly toward the nasopharynx. The inferior meatus, where the naso lacrimal duct opens, is located approximately 1 cm beyond the most anterior edge of the inferior turbinate. As the endoscope is advanced into the nose, the most important structure encountered is the middle turbinate. The middle turbinate is a key landmark in endoscopic sinus surgery. It has both a vertical component (lying in the sagittal plane, running from posterior to anterior) and a horizontal component (lying in the coronal plane, running from medial to lateral). Superiorly, the middle turbinate attaches to the skull base at the cribriform plate. As such, care should always be taken when manipulating the middle turbinate. The horizontal component of the middle turbinate is referred to as the basal (or ground) lamella, and it represents the dividing point between anterior and posterior ethmoid air cells. Posteriorly and inferiorly, the middle turbinate attaches to the lateral nasal wall at the crista ethmoidalis, just anterior to the sphenopalatine foramen. The uncinate process (UP) is the next key structure to be identified in endoscopic sinus surgery. This L-shaped bone of the lateral nasal wall forms the anterior border of the hiatus semilunaris, or the infundibulum. The infundibulum is the location of the ostiomeatal complex, where the natural ostium of the maxillary sinus opens. Once the uncinate process is removed, the natural maxillary ostium can be seen, typically just posterior to the uncinate process. The natural maxillary ostium is the destination for the mucociliary flow within the maxillary sinus. Therefore, for optimal results, the surgically enlarged maxillary antrostomy must include the natural ostium. In fact, failure to include the maxillary ostium in endoscopic surgical antrostomy is one of the key patterns of failure in functional endoscopic sinus surgery. The maxillary sinus is bordered superiorly by the inferior orbital wall, medially by the lateral nasal wall, and inferiorly by the alveolar portion of the maxillary bone. The next structure to be encountered is the ethmoid bulla, which is one of the most constant anterior ethmoidal air cells. It is just beyond the natural ostium of the maxillary sinus and forms the posterior border of the hiatus semilunaris. The lateral extent of the bulla is the lamina papyracea. Superiorly, the ethmoid bulla may extend all the way to the ethmoid roof (the skull base). Sometimes, a suprabullar recess may exist above the roof of the bulla. A careful preoperative review of the patient’s CT scan clarifies this relationship.

The ethmoid sinus consists of a variable number (typically 7-15) of air cells. The most lateral border of these air cells is the lamina papyracea, and the most superior border of these cells is the skull base. Supraorbital ethmoid cells may be present. Anterior ethmoid cells drain to the middle meatus, and the posterior cells drain into the superior meatus.

The sphenoid sinus is the most posterior of the paranasal sinuses, just superior to the nasopharynx and anterior and inferior to the sella turcica. Several important structures are related to the sphenoid sinus. The internal carotid artery is typically the most posterior and medial impression seen within the sphenoid sinus. In approximately 7% of cases, the bone is dehiscent. The optic nerve and its bony encasement produce an anterosuperior indentation within the roof of the sphenoid sinus. In 4% of cases, the bone surrounding the optic nerve is dehiscent. Therefore, guarded opening of the sphenoid sinus, typically at its natural ostium, is critical for a safe outcome. The location of the natural ostium of the sphenoid sinus is variable; approximately 60% are located medial to the superior turbinate, and 40% are located lateral to the superior turbinate.

The frontal recess, or the frontal outflow tract, is the tract that leads from the frontal sinus into the nasal cavity. Often, the ethmoid bulla is the posterior border of the frontal sinus outflow tract. Anteriorly, the frontal sinus outflow tract is bordered by the uncinate process or the agger nasi cells (frontal anterior ethmoid air cells). If any of these cells are enlarged or if scarring is present from a previous surgery, resultant outflow tract obstruction, leading to frontal sinusitis, may occur. Typically, the medial wall of the frontal recess is formed by the lamina papyracea. Intimate knowledge and understanding of the anatomy, in conjunction with a careful preoperative review of CT scans, are paramount in the safe and complete performance of endoscopic sinus surgery.

VARIATIONS OF NORMAL ANATOMY: The uncinate process (UP) anomalies are by far the most common anomalies encountered in the nasal cavity in individuals with chronic sinusitis. UP anomalies include elongated, lateral or medial deviation, and others.
- Elongation: The most common anomaly is elongation and apparent fusion of the UP tip to the floor of the ethmoid sinus However, although the semilunar hiatus appears to be absent, the maxillary sinus is fully developed. In FESS, the UP is not really fused and can still be surgically removed. This common distortion of the anatomy further restricts outflow of secretions by markedly narrowing the semilunar hiatus.
- Lateral deviation :If the UP tip fuses to the inferomedial floor of the orbit, the maxillary sinus ostium is absent. In addition, the UP tip is deviated in a lateral direction. This fusion is real and congenital in nature. As a result, no semilunar hiatus exists; therefore, no communication occurs between the maxillary sinus and the middle meatus. The EI ends in a blind pocket (i.e., recessus terminalis). The sinus is usually hypoplastic and nonaerated and therefore has never developed. The usual surgical incision at the base of the UP in FESS would result in direct orbital injury. The UP tip can also fuse directly to the lateral wall or lamina papyracea of the orbit, producing the same findings.
-Medial deviation :If the UP is deviated in a medial direction, it obstructs airflow into the middle meatus and may compress the mucosa of the nasal turbinate. The EI is patent and most likely communicates directly with the ethmoid ostia, thereby linking the maxillary sinus directly to the ethmoid sinuses.
- Pneumatization of the UP tip is another common anomaly. It expands the tip and may compromise the EI and semilunar hiatus.
- Spurs: In rare cases, a spur may arise from the UP and compromise the EI or middle meatus, depending on which way the spur tilts.
-Absence of uncinate process: Rarely, the UP may be absent entirely. The endoscopist may mistakenly incise the lateral maxillary sinus wall or, more importantly, the medial and inferior walls of the orbit, resulting in injury to the orbital contents.
- Onodi Cell :is a posterior ethmoid cell that has encroached upon the area of the sphenoid sinus. It is of considerable significance because in a large majority of these, a frankly dehiscent optic nerve, carotid artery or both may be present in variable locations. Several other variants have been described. Among these are the uncinate bulla, which although relatively infrequent, may alter the anatomy at the OMC. Others include Bulla Gali (5.4%), pterygoid pneumatization (43.6%), and anterior clinoid pneumatization (13.3%). Preoperative recognition of these variations is useful as these at times may require special attention in order to prevent postoperative recurrent disease, and more importantly, complications by allowing the surgeon to better estimate the limits of resection.

CONCHA ANOMALIES :

Concha anomalies are probably the most common anatomic variant of the nasal cavity, even more common than those of the UP. However, only a few concha anomalies lead to airway obstruction and chronic sinusitis with its attendant complications.
- Pneumatization: The most common anomaly is pneumatization of the concha, which is called a concha bullosa. As the name implies, portions of the concha are aerated; this occurs either in the vertical portion that attaches to the cribriform plate or lateral nasal cavity walls or in the concha or curved (shell-like) portions of the concha. Most cases of concha bullosa involve the middle turbinate, but the superior turbinate can also be involved. To date, concha bullosa of the inferior or supreme turbinate has not been reported. Pneumatization of the vertical or conchal portion is usually of no clinical significance. However, if the conchal portion of the middle turbinate is expanded significantly, the concha may compress or deviate the UP against the lateral wall of the nasal cavity and narrow the EI. Likewise, overexpansion compresses the middle meatus into which the ethmoid infundibula drain. Therefore, concha bullosa can also be assified into the group of lesions that narrows the EI.
- Paradoxical turbinates : Another anomaly of the nasal cavity with the potential for airway compromise and chronic sinusitis is the paradoxical turbinate. As with the concha bullosa, the most significant paradoxical turbinates involve the middle turbinate. Normally, the curved portion of the turbinate concha is adjacent to the nasal septum or points toward the septum. If the curve is exaggerated enough, it compresses and deviates the UP toward the lateral nasal cavity wall, compromising the EI. Usually, the paradoxical turbinates occur where the mucosa is hyperplastic. The overgrowth causes the mucosa to buckle and fold inward, with the resultant curve pointing toward the septum. The curved portion of the more posterior portion of the turbinate is typically directed toward the nasal septum. Occasionally, the concha mucosal portion may be deformed where the mucosa starts to fold inward and resembles a boxing glove with the knuckle portion directed toward the floor of the nasal cavity.
- Accessory turbinates: The presence of accessory turbinates is another anomaly that most often occurs in the region of the middle turbinates. Like the main turbinates, the accessory turbinates have a curved surface and a thin, inner, shell-like, bony structure. The bony structure contained within allows this anomaly to be differentiated from polyps that lack the bony portion. The accessory middle turbinates are either attached to the lateral nasal cavity wall or to the floor of the ethmoid sinus. Usually, the accessory turbinates are too small to compromise the airway.
- Duplicate turbinates : Another rare anomaly is a duplicate turbinate, in which 2 of the same turbinate occupy the same region. The vertical and conchal portions are exact copies of the original turbinate. When this occurs in the region of the middle turbinate, the presence of the additional turbinate can narrow and compromise the EI.
- Turbinate-to-turbinate attachment : Attachment of the turbinate to another turbinate, and not the lateral wall of the nasal cavity, is another and even more rare anomaly. Spur can arise from the turbinate and may interfere with the airflow, depending on its location.

OTHER CAUSES OF ETHMOID INFUNDIBULAR NARROWING:

-Haller air cell expansion. : Haller air cells occur along the inferomedial orbital wall and, if expanded, can narrow the EI at the maxillary sinus ostia. Controversy exists over what constitutes a Haller air cell. Generally, the Haller air cell is related to the inferior medial wall/floor of the orbit. The Haller air cell has been suggested to simply be an over expanded ethmoid air cell.
- Giant ethmoid bulla .: Overexpansion of the ethmoid sinuses or bulla (i.e., giant ethmoid bulla) is possible In this situation, downward bowing of the floor of the ethmoid sinus occurs, such that it encroaches on and narrows the semilunar hiatus. The downward bowing can also displace the UP in a lateral direction and narrow the EI.

-Nasal polyps : Nasal polyps can also affect the EI. Most nasal polyps arise from the region of the anterior ethmoid air cells and in relation to the UP, middle turbinate, and EI. Nasal polyps also originate from the anterior aspect of the ethmoid floor. In this location, the mass effect from the polyp can compromise the semilunar hiatus, extend into the EI, or extend medially between the UP and middle turbinate, occluding the middle meatus. Polyps tend to arise from areas where opposing mucosal surfaces are in contact with each other. In this sense, the UP anomalies with the mucosal surface contact may be a causative agent for polyp development. The soft tissue mass of nasal polyps obliterates the airways and makes CT interpretation difficult, particularly if the entire nasal cavity is filled with soft tissue. If large enough to cause bony changes, the nasal cavity polyp displaces the medial wall of the maxillary sinus in a lateral direction.
-Choanal polyps : Choanal polyps are a special subclass of polyps, arising from the maxillary sinus posterior or lateral walls. The polyp can initially grow into the maxillary sinus ostia and then into the EI, causing obstruction. Because of their origin with the maxillary sinus, choanal polyps displace the medial wall in a medial direction into the nasal cavity.

OTHER ANATOMIC CONSIDERATIONS IN FUNCTIONAL ENDOSCOPIC SINUS SURGERY :

Anatomic variations that do not lead to chronic sinusitis are also important for the endoscopists because they pose potential injury to the patient.
1.Fractures :Old fractures of the orbit or dehiscence of the lamina papyracea allow herniation of orbital contents into the ethmoid sinus, most notably orbital fat or middle rectus muscle. These structures and the arteries may be injured during FESS if the surgeon is unaware of these anatomic distortions. The herniated orbital contents are encountered after the UP is removed, the floor of the ethmoid sinus (bulla) is pierced, and the ethmoid sinus is entered.
2. UP anomalies: include fusion of the UP to the orbit wall or floor and absence of the UP. Fusion to the orbit may cause the endoscopist to inadvertently enter the orbit, injuring its contents during an attempt to resect the UP. Absence of the UP may cause the endoscopist to incorrectly identify the orbital wall or floor as the process, also leading to injury of the orbital contents.
3 Absence of basal or ground lamella : Absence of the basal or ground lamella is problematic only if FESS of the posterior OMC is being considered. Once the UP has been surgically removed, the endoscopist then punctures the floor of the ethmoid sinus. The basal or ground lamella separates the anterior two thirds of the ethmoid air cells from the posterior third. If the basal lamella is absent, the endoscopist may mistake the cribriform plate for the basal or ground lamella.
4.Bony septa: Other anomalies related to FESS of the posterior OMC include bony septa in the sphenoid sinus that attach directly to the bony carotid sulcus in the outer walls of the sphenoid sinus. Removing these septa may injure the carotid artery by fracturing the sulcus. Extensive skull base pneumatization may cause the Vidian nerve within the Vidian canal to appear as a bony elevated ridge that seems to float above the floor of the sphenoid sinus. What appears to be another bony septum contains the Vidian
nerve. Injury to this nerve mainly affects tearing.
5. Accessory turbinates : Accessory turbinates may be mistaken for polyps or, if large enough, for 1 of the 3 major turbinates. Choosing the wrong turbinate causes the endoscopist to be in the wrong meatus. However, most of these accessory turbinates are small.

References:

Ø 1 Bolger WE, Butzin CA, Parsons DS. Paranasal sinus bony anatomic variations and mucosal abnormalities: CT analysis for endoscopic sinus surgery. Laryngoscope 1991; 101: 56- 64.
Ø 2. Khalil HS, Nunez DA. Functional endoscopic sinus surgery for chronic rhino sinusitis. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD004458. DOI: 10.1002/14651858.CD004458.pub2.
Ø 3. e-Medicine – CT Scan, Nasal Cavity : Article by Charles Lee, MD , Functional Endoscopic Sinus Surgery : Article by Ankit M Patel, MD
Ø 4. Myerson MC. The natural orifice of the maxillary sinus. Arch Otolaryngol 1932; 15:80-91.
Ø 5. Ohnishi T, Tachibana T, Kaneko Y, Esaki S. High risk areas in endoscopic
sinus surgery and prevention of complications. Laryngoscope 1993; 103:1181-1185.
Ø 6. Stankiewicz JA. Blindness and intranasal endoscopic ethmoidectomy: prevention and management. Otolaryngol Head Neck Surg 1989; 101:320-329.
Ø 7. Stankiewicz JA. Cerebrospinal fluid fistula and endoscopic sinus surgery. Laryngoscope 1991; 101:250-256.
Ø 8. Stankiewicz JA. Complications in endoscopic intranasal ethmoidectomy: an update. Laryngoscope 1989; 99:686-690.
Ø 9. Abbel RW, Harnsberger HR, Sonkens J, Hunt S: Recurring patterns of inflammatory sinonasal disease demonstrated on screening sinus CT. AJNR Am J Neuroradiol 1992 May-Jun; 13(3): 903-12
Ø 10. Laine FJ, Smoker WR: The ostiomeatal unit and endoscopic surgery: anatomy, variations, and imaging findings in inflammatory diseases. AJR Am J Roentgenol 1992 Oct; 159(4): 849-57
Ø 11.Lee C, Given CA, Ritter JW: Nasal cavity anomalies in chronic sinusitis and FESS (functional endoscopic sinus surgery). Am J Roentgenol 2000; 173 (suppl 3): 80.
Ø 12. Mafee MF: Endoscopic sinus surgery: role of the radiologist. AJNR Am J Neuroradiol 1991 Sep-Oct; 12(5): 855-60
Ø 13. Stammberger H: Functional Endoscopic Sinus Surgery. 1991: 1-529. Wallace R, Salazar JE, Cowles S: The relationship between frontal sinus drainage and osteomeatal complex disease: a CT study in 217 patients.AJNR Am J Neuroradiol 1990 Jan-Feb; 11(1): 183-6
Ø 14. Zinreich SJ, Mattox DE, Kennedy DW, et al: Concha bullosa: CT valuation. J Comput Assist Tomogr 1988 Sep-Oct; 12(5): 778-8.

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Imaging Cafe: NEURO-RADIOLOGY PEARLS

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Imaging Cafe: NEURO-RADIOLOGY PEARLS

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ROLE OF IMAGING IN PAEDIATRIC EPILEPSIES

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Role of Imaging in pediatric epilepsy

Summary: An epileptic seizure is a clinical manifestation of abnormal, excessive neuronal activity arising in the gray matter of the cerebral cortex. Epilepsy in the pediatric population is fairly a common problem in day today practice. Recent advances in the imaging sciences has revolutionized the diagnosis and management of all types of epilepsies, especially with the advent of epilepsy surgery, detailed imaging has become mandatory. Yet the crucial aspect of assessment is not the radiological, but the clinical history and examination. Imaging is not required in all cases of childhood epilepsy, a proper clinical history is thus essential to identify the epileptic seizure. This group includes idiopathic generalized epilepsy (benign myoclonic epilepsy of infancy, childhood absence epilepsy, juvenile absence epilepsy juvenile myoclonic epilepsy) or benign epilepsy of childhood with Centro temporal spike where imaging is usually not necessary. CT and MRI are routinely used for imaging purpose ,though in an ideal situation MR should be the choice of imaging modality except in those cases calcification is to be ruled out, CT plays a major role. Out of common causes of epilepsy where imaging is necessary include hypoxic ischaemic encephalopathy, congenital abnormalities, mesial temporal sclerosis, infections, tumors and vascular malformation.

Diagnosis of epilepsy involves four stages.

· Recognition of epileptic seizure
· Classification of seizure types
· Identification of epilepsy syndrome
· Identification of the underlying etiology

These can be achieved by clinical including family history, examination findings, EEG including video imaging, blood tests, metabolic screening and lastly neuroimaging.

Indications for imaging

MRI is particularly indicated in patients with one or more of the following (Ideal practice)
International league against epilepsy.

· Onset of seizures at any age with evidence of a partial onset on clinical or EEG findings
· Onset of unclassified seizures or apparently generalized seizures in first year of life or in adulthood.
· Evidence of focal fixed deficit in clinical or EEG findings
· Failure to control the fits with first line of drugs
· Failure to control fits or change in the seizure pattern.

Neuroimaging is not done with a definite EEG evidence of idiopathic generalized epilepsy like benign myoclonic epilepsy of infancy, childhood absence epilepsy, Juvenile absence epilepsy ,JME and benign epilepsy of childhood with Centro temporal spikes.

Aim of neuroimaging
· To identify underlying pathology
· To aid the formulation of syndromic and etiological diagnosis.

Imaging modalities.
· MRI
· CT scanning
· Nuclear medicine SPECT and PET
· DSA
· Plain X-ray

MRI:
· Routine study,
· Dedicated seizure sequences,
· Functional MRI (fMRI)
· Spectroscopy

Routine MR study
Conventional sequences aims to find out any overt structural lesion in the brain. Axial, coronal and sagittal sequences with T1 and T2 weighted images are obtained. Additional FLAIR sequence is helpful to detect minor signal alteration.

Dedicated seizure protocol

This is necessary when no gross pathology is found in the routine sequences. This is done specially in the temporal lobe epilepsy to demonstrate any lesion in the structures of the medial temporal lobe.

· Heavily T2 weighted sequence in coronal plane
· T1 inversion recovery sequence in oblique coronal (the
right angles to the hippocampus).
· Hippocampal volumetric study to study the size and asymmetry
· T2 relaxometry ( T2 mapping) for Hippocampus and amygdala
· Spectroscopy

Functional MR

This is necessary when question of epilepsy surgery is considered. The technique used is called BOLD.(Blood Oxygen Level Dependant ).Patient is asked to perform some activity. The activated areas of the cerebral cortex will have increased blood flow without increase in the oxygen consumption suggesting anaerobic metabolism. This leads to increase in the oxyhaemoglobin level in the activated area. Deoxyhaemoglobin is paramagnetic and affects the T2 signal. The signal intensity in the activated area becomes different from the rest of the brain where the deoxyhaemoglobin predominates. In the activated area the T2 signal is preserved. This is the basis of BOLD. This difference in signal can be depicted in map. Increased BOLD signal can be obtained in the seizure focus in the interictal states in sites of EEG discharge. The main application of this in seizure is localization of motor strip.

Spectroscopy

By MR spectroscopy brain metabolites are analysed. Usually proton magnetic spectroscopy is performed. N-acetyl aspartate, choline and creatine. With neuronal loss the NAA level is reduced and in gliosis and astrocytosis the Creatine and Choline are increased. These can be analysed quantitavely or in graphical manner.

CT scanning
CT can be used as an initial screening procedure for overt tumours, infection etc, however MRI is preferred due to lack of radiation, increased spatial resolution and multiplanar capability. CT is specifically indicated to find out calcific foci.

Nuclear medicine: SPECT- ictal, post ictal and interictal SPECT
PET- glucose metabolism

Plain radiography- Limited role.

Imaging can be discussed according specific seizures

· Temporal lobe epilepsy
· Other Focal seizures
.

Temporal lobe epilepsy

This is complex partial seizure where the focus is generally in the temporal lobes. Causes can be divided into following category.

Mesial temporal sclerosis – Hippocampal sclerosis
- Hippocampal sclerosis and other temporal lobe abnormality
- Hippocampal sclerosis and extratemporal abnormalities
- Amygdalar sclerosis

Structural lesions Tumours
Infective lesions
Vascular malformation
Congenital and developmental lesions

Mesial temporal sclerosis

In this condition there is gliosis and neuronal loss involving the structures of mesial temporal lobe. Mesial temporal structures include hippocampus, parahippocampal gyrus, amygdala, entohinal cortex and subiculum.

Hippocampal sclerosis

This is condition in which there is focal sclerosis in the hippocampus. It is the most common cause of intractable epilepsy. Hippocampal sclerosis is important in epilepsy because
· It is the commonest lesion found in intractable epilepsy
· It is epileptogenic
· Identification of epileptic surgery

MR findings:

· Altered signal in the hippocampus
· Ipsilateral temporal horn dilatation
· Reduced hippocampal volume
· T2 relaxometry-increased signal
· Loss of grey white demarcation

Dual pathology:

Hippocampal sclerosis and extratemporal structural abnormality.

Other Focal seizures:

In most of the cases CT and routine MR sequences are enough to give an etiological diagnosis. The common causes of paediatric importance can be broadly classified as followed-:

· Congenital and developmental abnormality.
· Hypoxic ischaemic lesions
· White matter diseases
· Infections and infestation

Congenital and developmental abnormalities

Neuronal migration disorders:

This is one of the common conditions causing seizures in the paediatric population and most of the time this is under diagnosed. This is a condition were there is incomplete or abnormal migration of neurons from the germinal matrix to the cerebral cortex. During 7th weeks of gestation proliferation of neurons occur in the subependymal layer in the wall of lateral ventricles. This is area is called germinal matrix. From this region neurons start migrating to its final destination from 8th weeks of gestation and continues upto 20th week of gestation.

Lissencephaly:

Lissencephaly means smooth brain. There is paucity of sulcal development. If there is arrest of migration then it produces classical lissencephaly and when there is over migration the it produces cobblestone lissencephaly.
Classical lissencephaly the patient present with DDM and seizure. There is hypotonia at birth and spasticity at later life. There may be infantile spasm and medically refractory epilepsy at early age. Systemic abnormalities in heart, ear, eyes and kidneys may be present. On imaging there is smooth brain, shallow vertically oriented sylvian fissures giving rise to figure of 8 appearance. There is a zone of white matter separating the thin superficial cortical gray matter from thick layer of gray matter. There is reduced white matter density.

Heterotopia.

Collection of nerve cells in abnormal location due to arrest of migration. Patients invariably presents with seizure. Some of them presents with medically refractory epilepsy. Three types of heterotopia.

Subependymal
Focal sub-cortical.
Band heterotopia.

In subependymal heterotopia presents with normal development, normal motor function and seizure disorder. In focal subcortical Type there is medically refractory seizure and delayed motor development. In band heterotopia there is delayed developmental mile stones and seizure.

Schizencephaly

These are gray matter lined clefts extending from the pial surface to the subependymal layer. These may be closed lip when the lips are closed and open lip when the lips are open. This may be unilateral or bilateral, symmetrical or asymmetrical. Symptoms are more sever in the bilateral type. Varible motor dysfunction and seizures are common features.

Polymicrogyria.

Abnormal too many gyri separated by shallow sulci. Histologically there is laminar cortical necrosis in the cortical layer V .The cortical layer II, III, IV are normal. 90% patients present with seizures.

Focal cortical dysplasia

Focal abnormality in the cerebral cortex which may be trivial to be diagnosed in the MR scans. In mild cases there is mild blurring in the grey white junction. In others there may be flat smooth gyri( pachygyria) . Histologically they are not associated with abnormal balloon cells extending from cortex to the lateral ventricular wall.

Focal transmantle cortical dysplasia.

Here there is abnormal cells extending from the walls of the ventricles to the cortex. Histologically abnormal cells are seen in the cortex and in the underlying white matter. Abnormal cells include large atypical neurons, atypical glial cells, and balloon cells mixed with normal neurons. On imaging the involved portion is large, abnormal cortical pattern, broad gyri, irregular sulci.There is change in the signal intensity also .A Hyperintense linear line is seen extending from the abnormal cortex to the lateral ventricular wall. The gray white matter junction is blurred.

Neuro-cutaneous syndrome :

Four types of these, out of which the tuberous sclerosis usually presents with Seizure.

Tuberous sclerosis

These patients presents with classical triad.- seizure, adenoma sebaceum and delayed developmental milestones. The pathogenesis of this entity is uncertain, however this it thought to be due to disordered migration of dysgenetic neurons. There are four types of CNS lesions may be present.

· Cortical Tubers
· White matter abnormality
· Subependymal nodules
· Subependymal giant cell Astrocytoma.

Hypoxic ischaemic lesions

Localized infarction: -

These patients have variable presentation. Neonates typically present with seizures, hypotonia and lethargy whereas infants present with hand preference. In older children representation is like adults.
All most in 50 % of local brain infarction the cause is not known. In patients where cause is identified commonly related to cyanotic heart disease, sickle cell disease and moya moya disease. There are other metabolic causes of stroke in children. Imaging appearance are similar to that of older children and adult.

Diffuse ischaemic brain insult: –

Antenatal, postnatal and perinatal vascular events ,either hypoxic , ischaemic or hemorrhagic
May lead to wide range of abnormalities . Most of these insults will produce seizures at a later life .

Three factors are responsible for different pattern of brain injury.

Severity of hypotension.
Maturity of brain at the time of insult.
Duration of insult.

Severity of hypotension :-

In mild to moderate hypotension blood flow is shunted from anterior to posterior circulation. To maintain perfusion in brainstem, cerebellum and basal ganglia. Watershed zones of cerebral hemispheres are effected. In profound hypotension shunting is not possible so deeper structures like thalamus, basal ganglia and brain stem are affected.

Maturity of brain at the time of insult :-

Knowledge of blood circulation to the brain is necessary to understand the hypoxic damage to the neonatal brain. There are two sets of vessels. One cortical vessels the penetrate and they anastomose with the ventricular vessels in the periventricular region. In premature brain the cortical branches anastomose with the ventricular vessels in immediate periventricular region whereas in mature infant the anastomosing zone shifted to the peripherally. If ischaemic injury occurs in premature infant the infarctions are located in the immediate periventricular regions. But in mature infant or older children the infarctions are watershed zone and the subcortical periventricular white matter. The periventricular region contains the corticospinal tracts. These tracts are arranged in such a way that the immediate periventricular region contains fibres for the legs so bilateral involvement produces spastic diplegia at a later date. Again the geniculocalcarine fibres also travel in the peritrigonal region so most of these child suffers from visual abnormality.

CNS infections

· Both meningitis and encephalitis can produce seizures.
· Parenchymal infections like tuberculomas and cysticercosis frequently produces seizures. Cerebral abscesses rarely produce seizures.
· Congenital infections -

D/D of ring lesion.

Causes:

· Cysticercosis
· Tuberculoma
· Micro abscess
· Vascular lesion
· Demyelinating lesions

Cysticercosis Vs Tuberculoma
· Size
· Eccentric nodule
· Calcification
· Muliplicity

MRI in ring lesions

MRI is superior to CT scan in differentiating the different ring lesions. It is much more efficient diagnosing cysticercus cyst. A classical granuloma is identified by T2 hypointense Signal. A vascular lesion like aneurysm and AVM is seen as flow void if it associated with high flow.

Congenital infections:

Congenital infections include Cytomegalovirus, Toxoplasmosis, Rubella, Herpes simplex, HIV and Syphilis etc.

Cytomegalovirus infection: There are parenchymal calcifications predilection for the periventricular region. There is ventriculomegaly, atrophic changes, delayed Myelination and neuronal migration disorder.

Toxoplasmosis:

There are parenchymal calcifications not specific for periventricular region hydrocephalus and atrophy. No migrational disorder is noted.

Vascular malformation:

Four types vascular malformation is seen

· Arteriovenous malformation
· Cavernous angioma
· Capillary telangectasis
· Venous angioma.

Intracranial tumors

Though most of the tumors present with raised ICP some of the tumors grow very slowly like temporal lobe glioma, DNET, gangliglioma and oligodendroglioma etc.

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CURRICULUM VITAE – Dr Himadri Sikhor Das

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Curriculum Vitae

1. PERSONAL DETAILS

Name: Himadri Sikhor Das

Postal Address: C/o Dr. R. K. Das (FRCOG)
(Ex. Prof. Obs & Gyane, GMCH)
Amarawati Lane, Christianbasti,
P.O. – Dispur,
Guwahati -781005
Assam

Telephone: +91-98640 67142 (mobile)

+ 91-361- 2595082 (Residence)
+ 91-361-2595076 (Office)

Email: sekharhimadri@yahoo.com
drhsdas@gmail.com

Website: http//: www.radiozen.blogspot.com

Gender: Male Marital status: married

2. PROFESSIONAL EDUCATION AND QUALIFICATIONS

Graduate and Post graduate Qualifications :
· Post Doctoral Fellowship (PDCC) in Neuroradiology
Department of Radiology & Imaging,
Institute of Neurological Sciences (INS) and GNRC Heart Center, Guwahati, Assam, India
April 1999 to March 2000
· MD Radiology
Department of Radiology
Assam Medical College & Hospital (AMCH),
Dibrugarh, Assam, India
(WHO listed school)
December 1995 to February 1999

· MBBS
Guwahati Medical College & Hospital (GMCH)
Guwahati, Assam, India
(WHO listed school)
January 1989 to September 1993

3. TRAINING :

* Attended Critical Care Update in 2000 & also presented a paper titled “Role of Imaging In critically ill patients”
· Attended workshop in musculoskeletal USG in 2000 in Guwahati under aegis of IRIA branch.
· Underwent five months supervised training in INS(GNRC), Guwahati for CT, MRI and DSA under MD program.
· Attended regional conference (ANEICON) of neurosciences while pursuing postgraduate fellowship in Neuroradiology and also presented two papers titled:

(a) “MR morphology of intracranial tuberculomas” and
(b) “CT and MR imaging in cervical Myeloradiculopathies”

· Attended international conference of vascular and interventional radiology (ISVIR) in 2000 in New Delhi and also presented a paper titled “CT imaging in vertebrobasilar insufficiency:”
· Attended paediatric Neuroradiology conference in December 2003 in GMCH, Guwahati and presented a paper titled “Role of MR imaging in childhood epilepsies”
· Attended world MR end users conference (SIEMENS, MAGNETOM) in 2003 in Goa and presented a paper titled “MRCP evaluation in obstructive jaundice”.
· Participated in almost all-national level (IRIA), local and regional radiology conferences and CME programmes.
· Attended advanced life support / emergency / management of polytrauma camps & attending to deliveries as JHO for a period of one year in Red Cross Hospital, Guwahati. Attended flood & disaster relief camps under Guwahati Medical College Social Services Deptt while pursuing MBBS and during internship period.

PRESENT STATUS: Director & Radiologist,MATRIX

1. WORK HISTORY

Organization
Description of duties and experience

· Consultant Radiologist,
 Dr B.Barooah Cancer Institute (BBCI) from 1st March 2006 upto 31st
Oct 2006.

· Consultant Radiologist
September 2002 TO 28TH Feb, 2006
PRIMUS
· Primarily involved in imaging of emergency referred & trauma patients.
Modalities : CT Scan , MRI, USG, Color Doppler , X ray & allied procedures like IVP, barium studies and guided interventions.
· Administration of routine working protocols in the department, training of personnel, junior residents, PG’s
· Monitoring technical details and machinery, interacting with trade and industry personnel and generating inputs for overall improvement in departmental work

· Consultant Radiologist
 w.e.f. 10th December 2001 to 5th September 2002
Sehgal’s Neurological Research Centre (ADS Diagnostics)
 B – 21, Kailash Colony
New Delhi – 48
India
· Patient monitoring, scanning and reporting: CT, MRI, USG, Color Doppler and conventional studies in emergency, inhouse and OPD patients

· Senior Resident (Registrar)
w.e.f. 6th September 2000 to 6th December 2001
Department of Neuroradiology,
Cardiac & Neuro Centre,
All India Institute for Medical Sciences (AIIMS),
New Delhi – 29
India
· Conventional x-ray studies, USG, color doppler, CT, MRI and
interventional studies
· Regular Neuro radiological / clinical conferences
· Seminars
· Routine Emergencies
- Neuro-radiological
- Cardiac radiological
· Post Doctoral Fellowship in Neuroradiology
w.e.f 1st April 99 to 31st March 2000
Deptt. of Radiology & Imaging, Institute of Neurological Sciences (INS) and GNRC Heart Center, Guwahati-6, Assam, India
· Conventional x-ray studies, USG/color doppler, CT, MRI and
interventional studies
· Seminars / NR Conferences
· CME’s / Workshops
· Junior Medical Officer
w.e.f 31st Oct. 94 to 31st Sept. 95
Red Cross Hospital,
Navagiri Road,
Chandmari, Guwahati–3, Assam, India
Junior Residency in
· Surgery: 4 months
· Obs & Gynae: 4 months
· Casualty: 4 months
· Rotatory Clinical Internship
 w.e.f 20th Aug 93 to 3rd Sept. 94
Gauhati Medical College and Hospital (GMCH), Assam, India
· Two months each in general medicine, surgery, obs. and gyn. and PSM.
· One month each in ophthalmology, ENT, Casualty and Dermatology

2. Clinical Skills

Able to conduct, report and consult whole body CT, MRI, X-ray, USG, small parts, color doppler, IVP, X rays & allied conventional imaging procedures.

Possess special skills in:
: CT Guided interventions, FNAC
: Neuroradiology, Head & Neck including ENT (CT/MRI)
: CT stroke & trauma cases
: Thoracic & gastrointestinal CT

Research & training:

3. Topic of thesis undertaken under Post graduation program (M.D.) “An Evaluative study of the value of Iohexol Myelography in the Diagnosis of Lumbar Disc Lesions”.
4. Scientific paper presented in International Congress of Radiology (ICR, Sept. 98, New Delhi). “ Tuberculous Osteomyelitis of the skull”.
5. Research paper titled “HepatoCellular Carcinoma- Multiphasic Helical CT evaluation in 27 patients” presented at 14th Biennial Conference of Asia Pacific Congress For study of Liver (AALD-APASL 2004), New Delhi ,Dec”04. Abstract published in the Journal Of Gastroenterology & Hepatology.

6. Presented Scientific paper titled “ Cerebral hammartomatous lesions in clinically diagnosed children with NF-II – A pictorial essay” in the XVIII Symposium Neuroradiologicum (Neuroradiology World Congress held every four years) in Adelaide, Australia from 19th to 24th march, 2006

7. Presented Scientific paper titled “ Tubercular spondylodiskitis and cord Tuberculoma at the same vertebral level-A case report” in the XVIII Symposium Neuroradiologicum held in Adelaide, Australia from 19th to 24th march, 2006

MCI Registration No. : MBBS – 12662
(Assam Council of Medical Registration)
Specialist Regn No : (MD Radiology) 1595 AMC

University Registration No. : 26172 of 1997-1998

Professional Societies : Life Member of Indian Radiological and
Imaging Association (IRIA)
: Life Member Indian Medical Academy (IMA)
: Life Member Indian Society of Neuroradiology
(ISNR)
: Life Member Indian Red Cross-, Assam Branch
: Life Member International Youth
Hostels Association

Presently : Joint Secretary, Assam Branch, Indian Radiological & Imaging
Association (IRIA)
: Convenor ,City Chapter Assam Bracnch (IRIA)

thyroid opthalmopathy

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HEAD & NECK NODAL IMAGING

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Cervical Nodes

Variable size. Typically, as many as 75 nodes are located on each side of the neck. Nodes contain a sub capsular sinus below a prominent capsule, into which lymphatic fluid drains. This capsule is often the first site of metastatic growth. The fluid permeates into the substance of the node (composed of a cortex and a medulla) and exits through the hilum to enter more lymphatic vessels. These nodes are located between the superficial cervical and prevertebral fascia and, thus, are very amenable to surgical removal. The lymphatic fluid eventually enters the venous system at the junction of the internal jugular and subclavian veins. Many nodal descriptions exist today; Rouvière’s is the classic model.

The occipital nodes are in the superficial group, which includes 3-5 nodes. This group of nodes is localized between the sternocleidomastoid (SCM) and trapezius muscles, at the apex of the posterior triangle. These nodes are superficial to the splenius capitis. The deep group includes 1-3 nodes. This group of nodes is located deep to the splenius capitis and follows the course of the occipital artery. These nodes drain the scalp, the posterior portion of the neck, and the deep muscular layers of the neck.

The postauricular nodes vary in number from 2 to 4; they are located in the fibrous portion of the superior attachment of the SCM muscle to the mastoid process. Postauricular nodes drain the posterior parietal scalp and the skin of the mastoid region.

The parotid nodes can be divided into intraglandular and extraglandular groups. The extraglandular parotid nodes are located outside but adjacent to the parotid gland, where they drain the frontolateral scalp and face, the anterior aspects of the auricle, the external auditory canal, and the buccal mucosa. Embryologically, the lymphatic system develops before the parotid gland, which surrounds the intraglandular nodes as it develops. The intraglandular nodes drain the same regions as the extraglandularnodes, to which they interconnect and then drain into the upper jugular group of lymph nodes. As many as 20 parotid nodes may be found.

The submandibular nodes are divided into 5 groups:

Preglandular, postglandular, prevascular, postvascular, and intracapsular. The preglandular and prevascular groups are located anterior to the submandibular gland and facial artery, respectively. The postglandular and postvascular groups are posterior to these structures. Differing from the parotid gland in embryological development, there is no true intraglandular node; however, occasionally, a node has been identified inside the capsule of the gland. The submandibular nodes drain the ipsilateral upper and lower lip, cheek, nose, nasal mucosa, medial

canthus, anterior gingiva, anterior tonsillar pillar, soft palate, anterior two thirds of the tongue, and submandibular gland. The efferent vessels drain into the internal jugular nodes. For the submental nodes, 2-8 nodes are located in the soft tissues of the submental triangle between the platysma and mylohyoid muscles. These nodes drain the mentum, the middle portion of the lower lip, the anterior gingiva, and the anterior third of the tongue. The efferent vessels drain

into both the ipsilateral and contralateral submandibular nodes or into the internal jugular group.

The sublingual nodes are located along the collecting trunk of the tongue and sublingual gland and drain the anterior floor of the mouth and ventral surface of the tongue. These nodes subsequently drain into the submandibular or jugular group of nodes.

The retropharyngeal nodes are divided into a medial and lateral group, located between the pharynx and the prevertebral fascia. The lateral group, located at the level of the atlas near the internal carotid artery, consists of 1-3 nodes, which may extend to the skull base. The medial

group extends inferiorly to the postcricoid level. This group drains the posterior region of the nasal cavity, sphenoid and ethmoid sinuses, hard and soft palates, Nasopharynx, and posterior pharynx down to the postcricoid area. Management of these nodes must be considered if any

Malignancy arises from the mentioned drainage areas.

The anterior cervical nodes are divided into the anterior jugular chain and the juxtavisceral chain of nodes. The anterior jugular chain nodes follow the anterior jugular vein, located superficial to the strap muscles. These nodes drain the skin and muscles of the anterior portion of the neck, and the efferent vessels empty into the lower internal jugular nodes. The juxtavisceral nodes are separated into the prelaryngeal, parathyroid, pretracheal, and paratracheal nodes. Prelaryngeal nodes are located from the thyrohyoid membrane to the cricothyroid membrane and drain the larynx and the thyroid lobes. A single Delphian node is often found overlying the thyroid cartilage.

The pretracheal group consists of nodes between the isthmus of the thyroid gland down to the level of the innominate vein. Varying from 2-12 in number, these nodes drain the region of the thyroid gland and the trachea and receive afferent flow from the prelaryngeal group. The pretracheal efferents empty in the internal jugular group and the anterior superior mediastinal nodes.

The paratracheal nodes lie near the recurrent laryngeal nerve and drain the thyroid lobes, parathyroid glands, subglottic larynx, trachea, and upper esophagus. The efferent vessels travel to the lower jugular group or directly toward the junction of the internal jugular vein and the

Subclavian vein. The anterior nodes drain bilaterally because the midline of the neck has no division. Treatment must be planned accordingly when a tumor is located in subjacent draining areas.

The lateral cervical nodes are divided into superficial and deep groups. The superficial group follows the external jugular vein and drains into either the internal jugular or transverse cervical nodes of the deep group. The deep group forms a triangle bordered by the internal jugular nodes,

the spinal accessory nodes, and the transverse cervical nodes. The transverse cervical nodes, forming the base of the triangle, follow the transverse cervical vessels and may contain as many as 12 nodes. These nodes receive drainage from the spinal accessory group and from collecting

trunks of the skin of the neck and upper chest. The spinal accessory chain follows the nerve of the same name and may account for as many as 20 nodes. This chain receives lymph from the occipital, postauricular, and suprascapular nodes and from the posterior aspect of the scalp, nape of the neck, lateral aspect of the neck, and the shoulder.

The internal jugular chain consists of a large system covering the anterior and lateral aspects of the internal jugular vein, extending broadly from the digastric muscle superiorly to the subclavian vein inferiorly. As many as 30 of these nodes may exist, and they have been

arbitrarily divided into upper, middle, and lower groups. The efferents of these nodes eventually pass into the venous system via the thoracic duct on the left and multiple lymphatic channels on the right. These nodes drain all the other groups mentioned. Direct efferents may be present from

the nasal fossa, pharynx, tonsils, external and middle ear, Eustachian tube, tongue, palate, laryngopharynx, major salivary glands, thyroid, and parathyroid glands. Although fairly consistent, these drainage patterns are subject to alteration with malignant involvement or after radiotherapy. In such cases, rerouting is possible, with metastases arising in unusual sites.

Metastases have also been shown to skip first-echelon nodes and manifest in the lower internal jugular group.

The most widely accepted terminology was originally described by a group of head and neck

surgeons at Memorial Sloan-Kettering Hospital. This classification uses neck levels or zones and divides each side of the neck into 6 separate regions. Level I is bordered by the body of the mandible, anterior belly of the contralateral digastric muscle, and anterior and posterior bellies of

the ipsilateral digastric muscle. Two nodal subgroups are found. The submental group (Ia) is found in the submental triangle (anterior belly of the digastric muscles and the hyoid bone), and the submandibular group (Ib) is found within the submandibular triangle (anterior and posterior bellies of the digastric muscle and the body of the mandible).

The nodes found in level II are located around the upper third of the internal jugular vein, extending from the level of the carotid bifurcation inferiorly to the skull base superiorly. The lateral boundary is formed by the posterior border of the SCM muscle; the medial

boundary is formed by the stylohyoid muscle. Two subzones are also described; nodes located anterior to the spinal accessory nerve are part of level IIa, and those nodes posterior to the nerve are located in level IIb. The middle jugular lymph node group defines level III. Nodes are limited

by the carotid bifurcation superiorly and the cricothyroid membrane inferiorly. The lateral border is formed by the posterior border of the SCM muscle; the medial margin is formed by the lateral border of the sternohyoid muscle. Level lV contains the lower jugular group and extends superiorly from the omohyoid muscle to the clavicle inferiorly. The lateral border is formed by the posterior border of the SCM muscle; the medial margin is formed by the lateral border of the sternohyoid muscle. The lymph nodes found in level V are contained in the posterior neck triangle, bordered anteriorly by the posterior border of the SCM muscle, posteriorly by the anterior border of the trapezius, and inferiorly by the clavicle. Level V includes the spinal accessory, transverse cervical, and supraclavicular nodal groups. Level VI lymph nodes are located in the anterior compartment. These nodes surround the middle visceral structures of the neck from the level of the hyoid superiorly to the suprasternal notch inferiorly.

Evaluating neck metastases based on physical examination findings has been the classic method for patients with new tumors in the head and neck. The single most important factor in determining prognosis is whether nodal metastasis is present. Survival rates decrease by 50% when nodal metastases are present. Furthermore, the presence of cervical adenopathy

has been correlated with an increase in the rate of distant metastasis. During the clinical evaluation, carefully palpate the neck, with specific attention to location, size, firmness, and mobility of each node. Direct attention to nodes that appear fixed to underlying neurovascular

structures or visceral organs or that demonstrate skin infiltration. The description of each node becomes an important part of the medical record, which can be used to assess the response to treatment or the progression of the disease.

Unfortunately, clinical palpation of the neck demonstrates a large variation of findings among various examiners. Although both inexpensive to perform and repeat, palpation findings are generally accepted as inaccurate. Both the sensitivity and specificity are in the range of

60-70%, depending on the tumor studied. Because of the known low sensitivity and specificity of palpation, a neck side without palpable metastases is at risk of harboring occult metastasis, with the risk determined by the characteristics of the primary tumor. The incidence of false-negative (occult) nodes based on physical examination findings varies in the literature from 16-60%. Before the introduction of diagnostic imaging, particularly CT scan, clinical palpation was shown to be inadequate for detecting cervical metastasis. Soko et al reported that only 28% of occult cervical metastases were found by clinical palpation. Martis reported a 38% prevalence of occult metastasis based on clinical examination findings

Debate persists over the relative merits of imaging in the evaluation of the neck for metastatic disease. Studies that correlate radiologic and histopathologic findings show that early microscopic metastases can be present in nodes smaller than 10 mm that demonstrate no stigmata of neoplasia (i.e., central necrosis, extracapsular spread). Evidence of early metastatic disease in clinically occult nodes is minimal and may evade the efforts of the pathologist and radiologist.

Ultrasound Ultrasound is reported superior to clinical palpation for detecting lymph nodes and metastases. The advantages of ultrasound over other imaging modalities are price, low patient burden, and possibilities for follow-up.

Sonographs of metastatic lymph node disease characteristically find enlargement with a spherical shape. Commonly, nodes are hypo echoic, with a loss of hilar definition. In cases of extranodal spread with infiltrative growth, the borders are poorly defined. Common findings of metastases from squamous cell carcinoma are extranodal spread and central necrosis together with liquid areas in the lymph nodes. Lymph node metastases from malignant melanoma and papillary thyroid carcinoma have a nonechoic appearance that mimics a cystic lesion. Sonography also is useful for assessing invasion of the carotid artery and jugular vein. Because lymph nodes of borderline size cannot be reliably diagnosed using ultrasound alone, ultrasound-guided fine-needle aspiration and cytologic examination of the nodes in question can be easily performed. The result of the aspirate examination depends on the skill of the ultrasonographer and the quality of the specimen (ie, harboring an adequate number of representative cells). Using this technique, most studies report that a sensitivity of up to 70% can be obtained for the N0 neck.

CT scans

Since its debut in the 1970s, CT scans have been an invaluable tool in all fields of medicine, including the evaluation of head and neck cancer. Since the advent of high-resolution systems and specific contrast media,

fine-cut CT scanning has allowed the detection of pathological cervical nodes of smaller size that may be missed by clinical examination. CT scanning is now used routinely for the preoperative evaluation of the neck because, presumably, it helps decrease the incidence of occult cervical

Lymphadenopathy. Introduced in 1998, multiple-spiral CT scanning promises further improvement of temporal and spatial resolution (in the longitudinal axis). This technique permits rapid scanning of large volumes of tissue during quiet breathing. The volumetric helical data permit optical multiplanar and 3-dimensional reconstructions. Improvement of the assessment of tumor spread and lymph node metastases in arbitrary oblique planes is another

advantage of the spiral technique.

Criteria for the identification of questionable nodes are also evolving as technology advances. Central necrosis remains the most specific finding suggestive of nodal involvement, but its absence does not exclude metastasis. Unfortunately, metastasis is usually quite rare or not visible

in small lymph nodes, where detection would be crucial. Because of the higher imaging resolution, various studies have reduced the traditional values of 10-15 mm for a node to be suggestive. Many authors have proposed a minimal axial diameter of 11 mm for the submandibular triangle and 10 mm for the rest of the neck. Other criteria include the presence of groups of 3 or more borderline nodes and the loss of tissue planes.

Magnetic resonance imaging

The value of MRI is its excellent soft tissue resolution. MRI has surpassed CT scanning as the preferred study in the evaluation of cancer at primary sites such as the base of the tongue and the salivary glands. The sensitivity of MRI exceeds that of clinical palpation in detecting occult cervical lymphadenopathy. Size, the presence of multiple nodes, and necrosis are criteria shared by CT scanning and MRI imaging protocols. Most reports indicate that CT scanning still has an edge over MRI for detecting cervical nodal involvement. Advances in MRI technology (eg, fast

spin-echo imaging, fat suppression) have not yet surpassed the capacity of CT scanning to identify lymph nodes and to define nodal architecture. Central necrosis, as evaluated by unenhanced T1- and T2-weighted images, has been shown to provide an overall accuracy rate of 86-87% compared with CT scanning, which has an accuracy rate of 91-96%. The use of newer

Contrast media, especially supramagnetic contrast media agents, hopefully will improve the sensitivity of MRI.

Positron emission tomography and single-photon emission computed

tomography

Some studies have demonstrated that positron emission tomography may be able to detect nodal metastases in lymph nodes that are negative for disease based on CT scan or MRI findings. Single-photon emission computed tomography imaging with fluorodeoxyglucose or thallium also reportedly detects nodal metastases. The use of positron emission tomography in combination with immunoimaging using monoclonal antibodies might further enhance accuracy.

None of the currently available imaging techniques can help depict small tumor deposits inside lymph nodes. Characteristics of metastatic lymph nodes that can be depicted are the size and presence of noncontrast-enhancing parts inside metastatic lymph nodes caused by tumor necrosis, tumor keratinization, or cystic areas inside the tumor. Only rarely does tumoral tissue enhance more than reactive lymph node tissue; in these rare cases, the tumor can be visualized within a reactive lymph node.

Patients who need an evaluation for a possible nodal malignancy require a comprehensive multidisciplinary evaluation of all potential sites of drainage to that node to identify its primary source. This includes a thorough evaluation of potential primary sites using endoscopic techniques. When appropriate, include laryngoscopy, esophagoscopy, bronchoscopy, and examination of the nasopharynx. If no primary source is identified, taking blind mucosal biopsy samples of the most likely head and neck subsites is essential. Complete documentation of nodal characteristics by clinical examination and palpation guide the examiner in using adjunctive radiological tools to exclude occult nodal metastasis

References:

Chen Z, Malhotra PS, Thomas GR, et al: Expression of proinflammatory and proangiogenic cytokines in patients with head and neck cancer. Clin Cancer Res 1999 Jun; 5(6): 1369-79[Medline].

Curtin HD, Ishwaran H, Mancuso AA, et al: Comparison of CT and MR imaging in staging of neck metastases. Radiology 1998 Apr; 207(1): 123-30[Medline].

Haor SP, Ng SH: Magnetic resonance imaging versus clinical palpation in evaluating cervical metastasis from head and neck cancer. Otolaryngol Head Neck Surg 2000 Sep; 123(3): 324-7[Medline].

Merritt RM, Williams MF, James TH, Porubsky ES: Detection of cervical metastasis. A meta-analysis comparing computed tomography with physical examination. Arch Otolaryngol Head Neck Surg 1997 Feb; 123(2): 9-52[Medline].

Safa AA, Tran LM, Rege S, et al: The role of positron emission tomography in occult primary head and neck cancers. Cancer J Sci Am 1999 Jul-Aug; 5(4): 214-8[Medline].

Southwick, HW, Slaughter, DP, Trevino, ET: Elective neck dissection for intraoral cancer. Arch Surg 1960; 80: 905-9.

Stacker SA, Caesar C, Baldwin ME, et al: VEGF-D promotes the metastatic spread of tumor cells via the lymphatics. Nat Med 2001 Feb; 7(2): 186-91[Medline].

Van den Brekel MW: Lymph node metastases: CT and MRI. Eur J Radiol 2000 Mar; 33(3): 230-8[Medline].

Cervical Nodes

Variable size. Typically, as many as 75 nodes are located on each side of the neck. Nodes contain a sub capsular sinus below a prominent capsule, into which lymphatic fluid drains. This capsule is often the first site of metastatic growth. The fluid permeates into the substance of the node (composed of a cortex and a medulla) and exits through the hilum to enter more lymphatic vessels. These nodes are located between the superficial cervical and prevertebral fascia and, thus, are very amenable to surgical removal. The lymphatic fluid eventually enters the venous system at the junction of the internal jugular and subclavian veins. Many nodal descriptions exist today; Rouvière’s is the classic model.

The occipital nodes are in the superficial group, which includes 3-5 nodes. This group of nodes is localized between the sternocleidomastoid (SCM) and trapezius muscles, at the apex of the posterior triangle. These nodes are superficial to the splenius capitis. The deep group includes 1-3 nodes. This group of nodes is located deep to the splenius capitis and follows the course of the occipital artery. These nodes drain the scalp, the posterior portion of the neck, and the deep muscular layers of the neck.

The postauricular nodes vary in number from 2 to 4; they are located in the fibrous portion of the superior attachment of the SCM muscle to the mastoid process. Postauricular nodes drain the posterior parietal scalp and the skin of the mastoid region.

The parotid nodes can be divided into intraglandular and extraglandular groups. The extraglandular parotid nodes are located outside but adjacent to the parotid gland, where they drain the frontolateral scalp and face, the anterior aspects of the auricle, the external auditory canal, and the buccal mucosa. Embryologically, the lymphatic system develops before the parotid gland, which surrounds the intraglandular nodes as it develops. The intraglandular nodes drain the same regions as the extraglandularnodes, to which they interconnect and then drain into the upper jugular group of lymph nodes. As many as 20 parotid nodes may be found.

The submandibular nodes are divided into 5 groups:

Preglandular, postglandular, prevascular, postvascular, and intracapsular. The preglandular and prevascular groups are located anterior to the submandibular gland and facial artery, respectively. The postglandular and postvascular groups are posterior to these structures. Differing from the parotid gland in embryological development, there is no true intraglandular node; however, occasionally, a node has been identified inside the capsule of the gland. The submandibular nodes drain the ipsilateral upper and lower lip, cheek, nose, nasal mucosa, medial

canthus, anterior gingiva, anterior tonsillar pillar, soft palate, anterior two thirds of the tongue, and submandibular gland. The efferent vessels drain into the internal jugular nodes. For the submental nodes, 2-8 nodes are located in the soft tissues of the submental triangle between the platysma and mylohyoid muscles. These nodes drain the mentum, the middle portion of the lower lip, the anterior gingiva, and the anterior third of the tongue. The efferent vessels drain

into both the ipsilateral and contralateral submandibular nodes or into the internal jugular group.

The sublingual nodes are located along the collecting trunk of the tongue and sublingual gland and drain the anterior floor of the mouth and ventral surface of the tongue. These nodes subsequently drain into the submandibular or jugular group of nodes.

The retropharyngeal nodes are divided into a medial and lateral group, located between the pharynx and the prevertebral fascia. The lateral group, located at the level of the atlas near the internal carotid artery, consists of 1-3 nodes, which may extend to the skull base. The medial

group extends inferiorly to the postcricoid level. This group drains the posterior region of the nasal cavity, sphenoid and ethmoid sinuses, hard and soft palates, Nasopharynx, and posterior pharynx down to the postcricoid area. Management of these nodes must be considered if any

Malignancy arises from the mentioned drainage areas.

The anterior cervical nodes are divided into the anterior jugular chain and the juxtavisceral chain of nodes. The anterior jugular chain nodes follow the anterior jugular vein, located superficial to the strap muscles. These nodes drain the skin and muscles of the anterior portion of the neck, and the efferent vessels empty into the lower internal jugular nodes. The juxtavisceral nodes are separated into the prelaryngeal, parathyroid, pretracheal, and paratracheal nodes. Prelaryngeal nodes are located from the thyrohyoid membrane to the cricothyroid membrane and drain the larynx and the thyroid lobes. A single Delphian node is often found overlying the thyroid cartilage.

The pretracheal group consists of nodes between the isthmus of the thyroid gland down to the level of the innominate vein. Varying from 2-12 in number, these nodes drain the region of the thyroid gland and the trachea and receive afferent flow from the prelaryngeal group. The pretracheal efferents empty in the internal jugular group and the anterior superior mediastinal nodes.

The paratracheal nodes lie near the recurrent laryngeal nerve and drain the thyroid lobes, parathyroid glands, subglottic larynx, trachea, and upper esophagus. The efferent vessels travel to the lower jugular group or directly toward the junction of the internal jugular vein and the

Subclavian vein. The anterior nodes drain bilaterally because the midline of the neck has no division. Treatment must be planned accordingly when a tumor is located in subjacent draining areas.

The lateral cervical nodes are divided into superficial and deep groups. The superficial group follows the external jugular vein and drains into either the internal jugular or transverse cervical nodes of the deep group. The deep group forms a triangle bordered by the internal jugular nodes,

the spinal accessory nodes, and the transverse cervical nodes. The transverse cervical nodes, forming the base of the triangle, follow the transverse cervical vessels and may contain as many as 12 nodes. These nodes receive drainage from the spinal accessory group and from collecting

trunks of the skin of the neck and upper chest. The spinal accessory chain follows the nerve of the same name and may account for as many as 20 nodes. This chain receives lymph from the occipital, postauricular, and suprascapular nodes and from the posterior aspect of the scalp, nape of the neck, lateral aspect of the neck, and the shoulder.

The internal jugular chain consists of a large system covering the anterior and lateral aspects of the internal jugular vein, extending broadly from the digastric muscle superiorly to the subclavian vein inferiorly. As many as 30 of these nodes may exist, and they have been

arbitrarily divided into upper, middle, and lower groups. The efferents of these nodes eventually pass into the venous system via the thoracic duct on the left and multiple lymphatic channels on the right. These nodes drain all the other groups mentioned. Direct efferents may be present from

the nasal fossa, pharynx, tonsils, external and middle ear, Eustachian tube, tongue, palate, laryngopharynx, major salivary glands, thyroid, and parathyroid glands. Although fairly consistent, these drainage patterns are subject to alteration with malignant involvement or after radiotherapy. In such cases, rerouting is possible, with metastases arising in unusual sites.

Metastases have also been shown to skip first-echelon nodes and manifest in the lower internal jugular group.

The most widely accepted terminology was originally described by a group of head and neck

surgeons at Memorial Sloan-Kettering Hospital. This classification uses neck levels or zones and divides each side of the neck into 6 separate regions. Level I is bordered by the body of the mandible, anterior belly of the contralateral digastric muscle, and anterior and posterior bellies of

the ipsilateral digastric muscle. Two nodal subgroups are found. The submental group (Ia) is found in the submental triangle (anterior belly of the digastric muscles and the hyoid bone), and the submandibular group (Ib) is found within the submandibular triangle (anterior and posterior bellies of the digastric muscle and the body of the mandible).

The nodes found in level II are located around the upper third of the internal jugular vein, extending from the level of the carotid bifurcation inferiorly to the skull base superiorly. The lateral boundary is formed by the posterior border of the SCM muscle; the medial

boundary is formed by the stylohyoid muscle. Two subzones are also described; nodes located anterior to the spinal accessory nerve are part of level IIa, and those nodes posterior to the nerve are located in level IIb. The middle jugular lymph node group defines level III. Nodes are limited

by the carotid bifurcation superiorly and the cricothyroid membrane inferiorly. The lateral border is formed by the posterior border of the SCM muscle; the medial margin is formed by the lateral border of the sternohyoid muscle. Level lV contains the lower jugular group and extends superiorly from the omohyoid muscle to the clavicle inferiorly. The lateral border is formed by the posterior border of the SCM muscle; the medial margin is formed by the lateral border of the sternohyoid muscle. The lymph nodes found in level V are contained in the posterior neck triangle, bordered anteriorly by the posterior border of the SCM muscle, posteriorly by the anterior border of the trapezius, and inferiorly by the clavicle. Level V includes the spinal accessory, transverse cervical, and supraclavicular nodal groups. Level VI lymph nodes are located in the anterior compartment. These nodes surround the middle visceral structures of the neck from the level of the hyoid superiorly to the suprasternal notch inferiorly.

Evaluating neck metastases based on physical examination findings has been the classic method for patients with new tumors in the head and neck. The single most important factor in determining prognosis is whether nodal metastasis is present. Survival rates decrease by 50% when nodal metastases are present. Furthermore, the presence of cervical adenopathy

has been correlated with an increase in the rate of distant metastasis. During the clinical evaluation, carefully palpate the neck, with specific attention to location, size, firmness, and mobility of each node. Direct attention to nodes that appear fixed to underlying neurovascular

structures or visceral organs or that demonstrate skin infiltration. The description of each node becomes an important part of the medical record, which can be used to assess the response to treatment or the progression of the disease.

Unfortunately, clinical palpation of the neck demonstrates a large variation of findings among various examiners. Although both inexpensive to perform and repeat, palpation findings are generally accepted as inaccurate. Both the sensitivity and specificity are in the range of

60-70%, depending on the tumor studied. Because of the known low sensitivity and specificity of palpation, a neck side without palpable metastases is at risk of harboring occult metastasis, with the risk determined by the characteristics of the primary tumor. The incidence of false-negative (occult) nodes based on physical examination findings varies in the literature from 16-60%. Before the introduction of diagnostic imaging, particularly CT scan, clinical palpation was shown to be inadequate for detecting cervical metastasis. Soko et al reported that only 28% of occult cervical metastases were found by clinical palpation. Martis reported a 38% prevalence of occult metastasis based on clinical examination findings

Debate persists over the relative merits of imaging in the evaluation of the neck for metastatic disease. Studies that correlate radiologic and histopathologic findings show that early microscopic metastases can be present in nodes smaller than 10 mm that demonstrate no stigmata of neoplasia (i.e., central necrosis, extracapsular spread). Evidence of early metastatic disease in clinically occult nodes is minimal and may evade the efforts of the pathologist and radiologist.

Ultrasound Ultrasound is reported superior to clinical palpation for detecting lymph nodes and metastases. The advantages of ultrasound over other imaging modalities are price, low patient burden, and possibilities for follow-up.

Sonographs of metastatic lymph node disease characteristically find enlargement with a spherical shape. Commonly, nodes are hypo echoic, with a loss of hilar definition. In cases of extranodal spread with infiltrative growth, the borders are poorly defined. Common findings of metastases from squamous cell carcinoma are extranodal spread and central necrosis together with liquid areas in the lymph nodes. Lymph node metastases from malignant melanoma and papillary thyroid carcinoma have a nonechoic appearance that mimics a cystic lesion. Sonography also is useful for assessing invasion of the carotid artery and jugular vein. Because lymph nodes of borderline size cannot be reliably diagnosed using ultrasound alone, ultrasound-guided fine-needle aspiration and cytologic examination of the nodes in question can be easily performed. The result of the aspirate examination depends on the skill of the ultrasonographer and the quality of the specimen (ie, harboring an adequate number of representative cells). Using this technique, most studies report that a sensitivity of up to 70% can be obtained for the N0 neck.

CT scans

Since its debut in the 1970s, CT scans have been an invaluable tool in all fields of medicine, including the evaluation of head and neck cancer. Since the advent of high-resolution systems and specific contrast media,

fine-cut CT scanning has allowed the detection of pathological cervical nodes of smaller size that may be missed by clinical examination. CT scanning is now used routinely for the preoperative evaluation of the neck because, presumably, it helps decrease the incidence of occult cervical

Lymphadenopathy. Introduced in 1998, multiple-spiral CT scanning promises further improvement of temporal and spatial resolution (in the longitudinal axis). This technique permits rapid scanning of large volumes of tissue during quiet breathing. The volumetric helical data permit optical multiplanar and 3-dimensional reconstructions. Improvement of the assessment of tumor spread and lymph node metastases in arbitrary oblique planes is another

advantage of the spiral technique.

Criteria for the identification of questionable nodes are also evolving as technology advances. Central necrosis remains the most specific finding suggestive of nodal involvement, but its absence does not exclude metastasis. Unfortunately, metastasis is usually quite rare or not visible

in small lymph nodes, where detection would be crucial. Because of the higher imaging resolution, various studies have reduced the traditional values of 10-15 mm for a node to be suggestive. Many authors have proposed a minimal axial diameter of 11 mm for the submandibular triangle and 10 mm for the rest of the neck. Other criteria include the presence of groups of 3 or more borderline nodes and the loss of tissue planes.

Magnetic resonance imaging

The value of MRI is its excellent soft tissue resolution. MRI has surpassed CT scanning as the preferred study in the evaluation of cancer at primary sites such as the base of the tongue and the salivary glands. The sensitivity of MRI exceeds that of clinical palpation in detecting occult cervical lymphadenopathy. Size, the presence of multiple nodes, and necrosis are criteria shared by CT scanning and MRI imaging protocols. Most reports indicate that CT scanning still has an edge over MRI for detecting cervical nodal involvement. Advances in MRI technology (eg, fast

spin-echo imaging, fat suppression) have not yet surpassed the capacity of CT scanning to identify lymph nodes and to define nodal architecture. Central necrosis, as evaluated by unenhanced T1- and T2-weighted images, has been shown to provide an overall accuracy rate of 86-87% compared with CT scanning, which has an accuracy rate of 91-96%. The use of newer

Contrast media, especially supramagnetic contrast media agents, hopefully will improve the sensitivity of MRI.

Positron emission tomography and single-photon emission computed

tomography

Some studies have demonstrated that positron emission tomography may be able to detect nodal metastases in lymph nodes that are negative for disease based on CT scan or MRI findings. Single-photon emission computed tomography imaging with fluorodeoxyglucose or thallium also reportedly detects nodal metastases. The use of positron emission tomography in combination with immunoimaging using monoclonal antibodies might further enhance accuracy.

None of the currently available imaging techniques can help depict small tumor deposits inside lymph nodes. Characteristics of metastatic lymph nodes that can be depicted are the size and presence of noncontrast-enhancing parts inside metastatic lymph nodes caused by tumor necrosis, tumor keratinization, or cystic areas inside the tumor. Only rarely does tumoral tissue enhance more than reactive lymph node tissue; in these rare cases, the tumor can be visualized within a reactive lymph node.

Patients who need an evaluation for a possible nodal malignancy require a comprehensive multidisciplinary evaluation of all potential sites of drainage to that node to identify its primary source. This includes a thorough evaluation of potential primary sites using endoscopic techniques. When appropriate, include laryngoscopy, esophagoscopy, bronchoscopy, and examination of the nasopharynx. If no primary source is identified, taking blind mucosal biopsy samples of the most likely head and neck subsites is essential. Complete documentation of nodal characteristics by clinical examination and palpation guide the examiner in using adjunctive radiological tools to exclude occult nodal metastasis

References:

Chen Z, Malhotra PS, Thomas GR, et al: Expression of proinflammatory and proangiogenic cytokines in patients with head and neck cancer. Clin Cancer Res 1999 Jun; 5(6): 1369-79[Medline].

Curtin HD, Ishwaran H, Mancuso AA, et al: Comparison of CT and MR imaging in staging of neck metastases. Radiology 1998 Apr; 207(1): 123-30[Medline].

Haor SP, Ng SH: Magnetic resonance imaging versus clinical palpation in evaluating cervical metastasis from head and neck cancer. Otolaryngol Head Neck Surg 2000 Sep; 123(3): 324-7[Medline].

Merritt RM, Williams MF, James TH, Porubsky ES: Detection of cervical metastasis. A meta-analysis comparing computed tomography with physical examination. Arch Otolaryngol Head Neck Surg 1997 Feb; 123(2): 9-52[Medline].

Safa AA, Tran LM, Rege S, et al: The role of positron emission tomography in occult primary head and neck cancers. Cancer J Sci Am 1999 Jul-Aug; 5(4): 214-8[Medline].

Southwick, HW, Slaughter, DP, Trevino, ET: Elective neck dissection for intraoral cancer. Arch Surg 1960; 80: 905-9.

Stacker SA, Caesar C, Baldwin ME, et al: VEGF-D promotes the metastatic spread of tumor cells via the lymphatics. Nat Med 2001 Feb; 7(2): 186-91[Medline].

Van den Brekel MW: Lymph node metastases: CT and MRI. Eur J Radiol 2000 Mar; 33(3): 230-8[Medline].

Cervical Nodes

Variable size. Typically, as many as 75 nodes are located on each side of the neck. Nodes contain a sub capsular sinus below a prominent capsule, into which lymphatic fluid drains. This capsule is often the first site of metastatic growth. The fluid permeates into the substance of the node (composed of a cortex and a medulla) and exits through the hilum to enter more lymphatic vessels. These nodes are located between the superficial cervical and prevertebral fascia and, thus, are very amenable to surgical removal. The lymphatic fluid eventually enters the venous system at the junction of the internal jugular and subclavian veins. Many nodal descriptions exist today; Rouvière’s is the classic model.

The occipital nodes are in the superficial group, which includes 3-5 nodes. This group of nodes is localized between the sternocleidomastoid (SCM) and trapezius muscles, at the apex of the posterior triangle. These nodes are superficial to the splenius capitis. The deep group includes 1-3 nodes. This group of nodes is located deep to the splenius capitis and follows the course of the occipital artery. These nodes drain the scalp, the posterior portion of the neck, and the deep muscular layers of the neck.

The postauricular nodes vary in number from 2 to 4; they are located in the fibrous portion of the superior attachment of the SCM muscle to the mastoid process. Postauricular nodes drain the posterior parietal scalp and the skin of the mastoid region.

The parotid nodes can be divided into intraglandular and extraglandular groups. The extraglandular parotid nodes are located outside but adjacent to the parotid gland, where they drain the frontolateral scalp and face, the anterior aspects of the auricle, the external auditory canal, and the buccal mucosa. Embryologically, the lymphatic system develops before the parotid gland, which surrounds the intraglandular nodes as it develops. The intraglandular nodes drain the same regions as the extraglandularnodes, to which they interconnect and then drain into the upper jugular group of lymph nodes. As many as 20 parotid nodes may be found.

The submandibular nodes are divided into 5 groups:

Preglandular, postglandular, prevascular, postvascular, and intracapsular. The preglandular and prevascular groups are located anterior to the submandibular gland and facial artery, respectively. The postglandular and postvascular groups are posterior to these structures. Differing from the parotid gland in embryological development, there is no true intraglandular node; however, occasionally, a node has been identified inside the capsule of the gland. The submandibular nodes drain the ipsilateral upper and lower lip, cheek, nose, nasal mucosa, medial

canthus, anterior gingiva, anterior tonsillar pillar, soft palate, anterior two thirds of the tongue, and submandibular gland. The efferent vessels drain into the internal jugular nodes. For the submental nodes, 2-8 nodes are located in the soft tissues of the submental triangle between the platysma and mylohyoid muscles. These nodes drain the mentum, the middle portion of the lower lip, the anterior gingiva, and the anterior third of the tongue. The efferent vessels drain

into both the ipsilateral and contralateral submandibular nodes or into the internal jugular group.

The sublingual nodes are located along the collecting trunk of the tongue and sublingual gland and drain the anterior floor of the mouth and ventral surface of the tongue. These nodes subsequently drain into the submandibular or jugular group of nodes.

The retropharyngeal nodes are divided into a medial and lateral group, located between the pharynx and the prevertebral fascia. The lateral group, located at the level of the atlas near the internal carotid artery, consists of 1-3 nodes, which may extend to the skull base. The medial

group extends inferiorly to the postcricoid level. This group drains the posterior region of the nasal cavity, sphenoid and ethmoid sinuses, hard and soft palates, Nasopharynx, and posterior pharynx down to the postcricoid area. Management of these nodes must be considered if any

Malignancy arises from the mentioned drainage areas.

The anterior cervical nodes are divided into the anterior jugular chain and the juxtavisceral chain of nodes. The anterior jugular chain nodes follow the anterior jugular vein, located superficial to the strap muscles. These nodes drain the skin and muscles of the anterior portion of the neck, and the efferent vessels empty into the lower internal jugular nodes. The juxtavisceral nodes are separated into the prelaryngeal, parathyroid, pretracheal, and paratracheal nodes. Prelaryngeal nodes are located from the thyrohyoid membrane to the cricothyroid membrane and drain the larynx and the thyroid lobes. A single Delphian node is often found overlying the thyroid cartilage.

The pretracheal group consists of nodes between the isthmus of the thyroid gland down to the level of the innominate vein. Varying from 2-12 in number, these nodes drain the region of the thyroid gland and the trachea and receive afferent flow from the prelaryngeal group. The pretracheal efferents empty in the internal jugular group and the anterior superior mediastinal nodes.

The paratracheal nodes lie near the recurrent laryngeal nerve and drain the thyroid lobes, parathyroid glands, subglottic larynx, trachea, and upper esophagus. The efferent vessels travel to the lower jugular group or directly toward the junction of the internal jugular vein and the

Subclavian vein. The anterior nodes drain bilaterally because the midline of the neck has no division. Treatment must be planned accordingly when a tumor is located in subjacent draining areas.

The lateral cervical nodes are divided into superficial and deep groups. The superficial group follows the external jugular vein and drains into either the internal jugular or transverse cervical nodes of the deep group. The deep group forms a triangle bordered by the internal jugular nodes,

the spinal accessory nodes, and the transverse cervical nodes. The transverse cervical nodes, forming the base of the triangle, follow the transverse cervical vessels and may contain as many as 12 nodes. These nodes receive drainage from the spinal accessory group and from collecting

trunks of the skin of the neck and upper chest. The spinal accessory chain follows the nerve of the same name and may account for as many as 20 nodes. This chain receives lymph from the occipital, postauricular, and suprascapular nodes and from the posterior aspect of the scalp, nape of the neck, lateral aspect of the neck, and the shoulder.

The internal jugular chain consists of a large system covering the anterior and lateral aspects of the internal jugular vein, extending broadly from the digastric muscle superiorly to the subclavian vein inferiorly. As many as 30 of these nodes may exist, and they have been

arbitrarily divided into upper, middle, and lower groups. The efferents of these nodes eventually pass into the venous system via the thoracic duct on the left and multiple lymphatic channels on the right. These nodes drain all the other groups mentioned. Direct efferents may be present from

the nasal fossa, pharynx, tonsils, external and middle ear, Eustachian tube, tongue, palate, laryngopharynx, major salivary glands, thyroid, and parathyroid glands. Although fairly consistent, these drainage patterns are subject to alteration with malignant involvement or after radiotherapy. In such cases, rerouting is possible, with metastases arising in unusual sites.

Metastases have also been shown to skip first-echelon nodes and manifest in the lower internal jugular group.

The most widely accepted terminology was originally described by a group of head and neck

surgeons at Memorial Sloan-Kettering Hospital. This classification uses neck levels or zones and divides each side of the neck into 6 separate regions. Level I is bordered by the body of the mandible, anterior belly of the contralateral digastric muscle, and anterior and posterior bellies of

the ipsilateral digastric muscle. Two nodal subgroups are found. The submental group (Ia) is found in the submental triangle (anterior belly of the digastric muscles and the hyoid bone), and the submandibular group (Ib) is found within the submandibular triangle (anterior and posterior bellies of the digastric muscle and the body of the mandible).

The nodes found in level II are located around the upper third of the internal jugular vein, extending from the level of the carotid bifurcation inferiorly to the skull base superiorly. The lateral boundary is formed by the posterior border of the SCM muscle; the medial

boundary is formed by the stylohyoid muscle. Two subzones are also described; nodes located anterior to the spinal accessory nerve are part of level IIa, and those nodes posterior to the nerve are located in level IIb. The middle jugular lymph node group defines level III. Nodes are limited

by the carotid bifurcation superiorly and the cricothyroid membrane inferiorly. The lateral border is formed by the posterior border of the SCM muscle; the medial margin is formed by the lateral border of the sternohyoid muscle. Level lV contains the lower jugular group and extends superiorly from the omohyoid muscle to the clavicle inferiorly. The lateral border is formed by the posterior border of the SCM muscle; the medial margin is formed by the lateral border of the sternohyoid muscle. The lymph nodes found in level V are contained in the posterior neck triangle, bordered anteriorly by the posterior border of the SCM muscle, posteriorly by the anterior border of the trapezius, and inferiorly by the clavicle. Level V includes the spinal accessory, transverse cervical, and supraclavicular nodal groups. Level VI lymph nodes are located in the anterior compartment. These nodes surround the middle visceral structures of the neck from the level of the hyoid superiorly to the suprasternal notch inferiorly.

Evaluating neck metastases based on physical examination findings has been the classic method for patients with new tumors in the head and neck. The single most important factor in determining prognosis is whether nodal metastasis is present. Survival rates decrease by 50% when nodal metastases are present. Furthermore, the presence of cervical adenopathy

has been correlated with an increase in the rate of distant metastasis. During the clinical evaluation, carefully palpate the neck, with specific attention to location, size, firmness, and mobility of each node. Direct attention to nodes that appear fixed to underlying neurovascular

structures or visceral organs or that demonstrate skin infiltration. The description of each node becomes an important part of the medical record, which can be used to assess the response to treatment or the progression of the disease.

Unfortunately, clinical palpation of the neck demonstrates a large variation of findings among various examiners. Although both inexpensive to perform and repeat, palpation findings are generally accepted as inaccurate. Both the sensitivity and specificity are in the range of

60-70%, depending on the tumor studied. Because of the known low sensitivity and specificity of palpation, a neck side without palpable metastases is at risk of harboring occult metastasis, with the risk determined by the characteristics of the primary tumor. The incidence of false-negative (occult) nodes based on physical examination findings varies in the literature from 16-60%. Before the introduction of diagnostic imaging, particularly CT scan, clinical palpation was shown to be inadequate for detecting cervical metastasis. Soko et al reported that only 28% of occult cervical metastases were found by clinical palpation. Martis reported a 38% prevalence of occult metastasis based on clinical examination findings

Debate persists over the relative merits of imaging in the evaluation of the neck for metastatic disease. Studies that correlate radiologic and histopathologic findings show that early microscopic metastases can be present in nodes smaller than 10 mm that demonstrate no stigmata of neoplasia (i.e., central necrosis, extracapsular spread). Evidence of early metastatic disease in clinically occult nodes is minimal and may evade the efforts of the pathologist and radiologist.

Ultrasound Ultrasound is reported superior to clinical palpation for detecting lymph nodes and metastases. The advantages of ultrasound over other imaging modalities are price, low patient burden, and possibilities for follow-up.

Sonographs of metastatic lymph node disease characteristically find enlargement with a spherical shape. Commonly, nodes are hypo echoic, with a loss of hilar definition. In cases of extranodal spread with infiltrative growth, the borders are poorly defined. Common findings of metastases from squamous cell carcinoma are extranodal spread and central necrosis together with liquid areas in the lymph nodes. Lymph node metastases from malignant melanoma and papillary thyroid carcinoma have a nonechoic appearance that mimics a cystic lesion. Sonography also is useful for assessing invasion of the carotid artery and jugular vein. Because lymph nodes of borderline size cannot be reliably diagnosed using ultrasound alone, ultrasound-guided fine-needle aspiration and cytologic examination of the nodes in question can be easily performed. The result of the aspirate examination depends on the skill of the ultrasonographer and the quality of the specimen (ie, harboring an adequate number of representative cells). Using this technique, most studies report that a sensitivity of up to 70% can be obtained for the N0 neck.

CT scans

Since its debut in the 1970s, CT scans have been an invaluable tool in all fields of medicine, including the evaluation of head and neck cancer. Since the advent of high-resolution systems and specific contrast media,

fine-cut CT scanning has allowed the detection of pathological cervical nodes of smaller size that may be missed by clinical examination. CT scanning is now used routinely for the preoperative evaluation of the neck because, presumably, it helps decrease the incidence of occult cervical

Lymphadenopathy. Introduced in 1998, multiple-spiral CT scanning promises further improvement of temporal and spatial resolution (in the longitudinal axis). This technique permits rapid scanning of large volumes of tissue during quiet breathing. The volumetric helical data permit optical multiplanar and 3-dimensional reconstructions. Improvement of the assessment of tumor spread and lymph node metastases in arbitrary oblique planes is another

advantage of the spiral technique.

Criteria for the identification of questionable nodes are also evolving as technology advances. Central necrosis remains the most specific finding suggestive of nodal involvement, but its absence does not exclude metastasis. Unfortunately, metastasis is usually quite rare or not visible

in small lymph nodes, where detection would be crucial. Because of the higher imaging resolution, various studies have reduced the traditional values of 10-15 mm for a node to be suggestive. Many authors have proposed a minimal axial diameter of 11 mm for the submandibular triangle and 10 mm for the rest of the neck. Other criteria include the presence of groups of 3 or more borderline nodes and the loss of tissue planes.

Magnetic resonance imaging

The value of MRI is its excellent soft tissue resolution. MRI has surpassed CT scanning as the preferred study in the evaluation of cancer at primary sites such as the base of the tongue and the salivary glands. The sensitivity of MRI exceeds that of clinical palpation in detecting occult cervical lymphadenopathy. Size, the presence of multiple nodes, and necrosis are criteria shared by CT scanning and MRI imaging protocols. Most reports indicate that CT scanning still has an edge over MRI for detecting cervical nodal involvement. Advances in MRI technology (eg, fast

spin-echo imaging, fat suppression) have not yet surpassed the capacity of CT scanning to identify lymph nodes and to define nodal architecture. Central necrosis, as evaluated by unenhanced T1- and T2-weighted images, has been shown to provide an overall accuracy rate of 86-87% compared with CT scanning, which has an accuracy rate of 91-96%. The use of newer

Contrast media, especially supramagnetic contrast media agents, hopefully will improve the sensitivity of MRI.

Positron emission tomography and single-photon emission computed

tomography

Some studies have demonstrated that positron emission tomography may be able to detect nodal metastases in lymph nodes that are negative for disease based on CT scan or MRI findings. Single-photon emission computed tomography imaging with fluorodeoxyglucose or thallium also reportedly detects nodal metastases. The use of positron emission tomography in combination with immunoimaging using monoclonal antibodies might further enhance accuracy.

None of the currently available imaging techniques can help depict small tumor deposits inside lymph nodes. Characteristics of metastatic lymph nodes that can be depicted are the size and presence of noncontrast-enhancing parts inside metastatic lymph nodes caused by tumor necrosis, tumor keratinization, or cystic areas inside the tumor. Only rarely does tumoral tissue enhance more than reactive lymph node tissue; in these rare cases, the tumor can be visualized within a reactive lymph node.

Patients who need an evaluation for a possible nodal malignancy require a comprehensive multidisciplinary evaluation of all potential sites of drainage to that node to identify its primary source. This includes a thorough evaluation of potential primary sites using endoscopic techniques. When appropriate, include laryngoscopy, esophagoscopy, bronchoscopy, and examination of the nasopharynx. If no primary source is identified, taking blind mucosal biopsy samples of the most likely head and neck subsites is essential. Complete documentation of nodal characteristics by clinical examination and palpation guide the examiner in using adjunctive radiological tools to exclude occult nodal metastasis

References:

Chen Z, Malhotra PS, Thomas GR, et al: Expression of proinflammatory and proangiogenic cytokines in patients with head and neck cancer. Clin Cancer Res 1999 Jun; 5(6): 1369-79[Medline].

Curtin HD, Ishwaran H, Mancuso AA, et al: Comparison of CT and MR imaging in staging of neck metastases. Radiology 1998 Apr; 207(1): 123-30[Medline].

Haor SP, Ng SH: Magnetic resonance imaging versus clinical palpation in evaluating cervical metastasis from head and neck cancer. Otolaryngol Head Neck Surg 2000 Sep; 123(3): 324-7[Medline].

Merritt RM, Williams MF, James TH, Porubsky ES: Detection of cervical metastasis. A meta-analysis comparing computed tomography with physical examination. Arch Otolaryngol Head Neck Surg 1997 Feb; 123(2): 9-52[Medline].

Safa AA, Tran LM, Rege S, et al: The role of positron emission tomography in occult primary head and neck cancers. Cancer J Sci Am 1999 Jul-Aug; 5(4): 214-8[Medline].

Southwick, HW, Slaughter, DP, Trevino, ET: Elective neck dissection for intraoral cancer. Arch Surg 1960; 80: 905-9.

Stacker SA, Caesar C, Baldwin ME, et al: VEGF-D promotes the metastatic spread of tumor cells via the lymphatics. Nat Med 2001 Feb; 7(2): 186-91[Medline].

Van den Brekel MW: Lymph node metastases: CT and MRI. Eur J Radiol 2000 Mar; 33(3): 230-8[Medline].

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MATRIX IMAGING

Posted by Bobby on

Outline
1. The prime objective of the project is to establish a state-of-art Diagnostic healthcare facility in Guwahati, the gateway of the Seven States of North Eastern India, which will be comparable to the best Diagnostic Centres in terms of equipment, amenities, manpower and most of all, quality of Diagnosis.
2. The project is being initiated by a group of four RadioDiagnosis Specialists, who perceive great scope for private sector participation in the delivery of quality health care in the country. The present complex in Central Guwahati has been taken over on a long-term lease for the Project. Ideally situated in Central Guwahati on G.S. Road, the site is easily accessible both to patients and physicians.

3. In terms of Diagnostic services, the focus is on Hi-tech Diagnostic Imaging services, which are in great demand in the region. Some of the facilities offered will include: CT scanning including angiographies & interventional studies, color doppler, X-ray with IITV & Pathology equipments

7. MATRIX is provided with high-tech broadband communication facilities to facilitate instant consultation, up-to-date information and medical record transfer in cases of emergency, complicated and acute cases.

8. MATRIX also plans to set up:
a. An ongoing continuing education training programme to keep abreast with the latest international medical developments.
b. A vocational training programme for Radiographers.

The facility is managed by a group of highly trained professionals and assisted by a Hospital & Healthcare Management Committee constituted by highly placed people from all spheres of society. An Advisory Committee also monitors the quality of services. The catchment market includes the state of Assam and the 7 Northeast states. This alone encompasses a market of over 22 million people within the country itself.
Additionally, located in the heart of the South East Asian Growth Quadrangle as identified by the Asian Development Bank AIDC is also ideally located to cater in future to the Far-East Asian countries like Myanmar, Thailand, Vietnam, Malaysia, Indonesia etc., and offering the people of these areas high quality medical care at a much lower cost. This area covers over half of Asia’s population.

Health Care Scenario
With a rapidly expanding population of around 880 Million, India has a very inadequate health care delivery system even though quality of medical education is quite good, and by and large health care professionals are competent. As the market place privatises, and healthcare comes to be considered an industry by the Government of India, corporate health-care emerges as a lucrative investment to many. Of late, some large private tertiary care hospitals have even successfully raised money through public offerings.
Most diagnostic centres lack the benefit of collective strength of Doctors providing full time services. Moreover, there remains a large unfulfilled demand for specialised and advanced diagnostic unit under one roof

Admittedly, over the past few years or so, some large, modern, corporate hospitals, such as those set up under the aegis of the Apollo group in some cities in India, have demonstrated that these are expanding. Through branches, new projects on similar lines are being undertaken. This testifies to the fact that demand remains unfulfilled. In this scenario there is a huge potential on Diagnostic Centres. The general hospitals, nursing homes, practising physicians, surgeons and clinics of Guwahati will act as feeders to the centre.

Presently almost all the modern facilities are only with one privately managed centre. There is ample scope of another full-fledged Diagnostic Center with MRI. The huge population remain without good facility of Diagnostic Imaging.
Demand Estimation
It has been found that many patients from Guwahati, other parts of Assam, as well as from the surrounding North Eastern States, like Sikkim, Nagaland, Manipur, Mizoram, Meghalaya & Tripura, currenly travel far to avail specialised treatment. This is because the existing Diagnostic Centre fails to provide them with similar standards of service and professionalism. Facilities are not the only important point. What is even more important is Quality of Care.
Similarly many patients, who have traditionally been coming to Guwahati from neighbouring countries like Bangladesh and Bhutan to avail treatment, are also going elsewhere for treatment as the existing Diagnostic Centres are failing to provide the procedures and standards they seek.

Site Details
The building is situated 20 metres away from the main G.S Road with open access. Building comprises of carpet area of 2750sq feet for radiology in the ground floor & 1500 sq. feet for offices , Pathology & OPG sections in the first & second floors. Front side is open which is used to park few cars. Building is well ventilated and aerated from all the sides. Presently Phase I is operating from ground floor and first floor & further floors will be added in the same building for later upgradations.

MEDICAL FACILITIES AVAILABLE

Diagnostic Radiology: -

Ø Ultrasonography

Ø Whole Body high resolution color Doppler Imaging

Ø X Ray (500mA) Radiography with and IITV Fluoroscopy
Barium studies
IVP
MCU, RGU
Routine X-ray examinations

Ø Computed Tomography (Multi Slice CT Scanner)
· Routine – Trauma, stroke and cancer patients
· Multiphasic studies for liver, pancreas, kidneys
· High resolution scanning for ear, sinuses and lungs
· CT angiographies
· CT guided biopsies and other interventions
· CT Myelography
· CT enteroclysis
· Cancer treatment planning
· Volume Rendering
· Sub Milimeter Scanning
· High Resolution Scan for HRCT.

Ø Pathology including Histopathology & Biochemistry

Ø Diagnostic Cardiology: -
o Echo Cardiography
· Doppler Studies
o ECG.

Amenities at AIDC
· Central air-conditioning & climate control
· Emergency Reporting of x-ray, USG, Color Doppler & CT
· Ambulance facilities

With well-directed entrepreneurial energy MATRIX has been trying to bring together the two crucial elements of capital and technical expertise and have begun building a highly advanced, diagnostic healthcare set-up in Guwahati.

ADVANTAGES OF LOW RADIATION MULTISLICE SPIRAL CT SIEMENS “SOMATOM SPIRIT”. FIRST INSTALLATION IN GUWAHATI CITY

Syngo VRT: Advanced 3D functionality as an extension to the basic 3D viewer, containing volume rendering Technique (VRT) and advanced editing functions. Direct Volume Rendering Technique (VRT) for viewing 3D-volumes.

CT Angiography:
Software program for the reconstruction of oblique projections from the images of a spiral data file,
for the display and diagnosis of aneurysms, plaques, stenoses, vascular anomalies or vascular
origins. The oblique projections are reconstructed around a pre-defined axis, whereby for each
oblique projection the maximum CT value in this direction is selected. The resulting series can be
viewed with a 3D image effect using the Cine function.
syngo

3D SSD:
Software program for the three-dimensional display of surfaces from a series of contiguous slices.
Used to display and analyze complex anatomies, e.g. skull, pelvis and hips, for the purpose of
planning surgical interventions. The 3D objects can be tilted and rotated on the monitor and/or
displayed in non-Transaxial views in real time.

Real Time Display
Software program that provides instantaneous 512 x 512 image display coinciding with the actual
tube/detector position. This feature is especially useful for situations when real-time viewing of a
scan is desired.

CINE Display:
Presentation technique for time-related processes and 3D survey of an entire anatomic region
achieved with a fast frame rate. A series of up to 1,000 images can be displayed in a 512 x 512 image matrix at a rate of 10 f/s.

Head Arm Support
For comfortable leg and arm positioning during chest, abdominal and lumbar spine examinations
.
Coronal supine head holder
For coronal slices in the skull with patient in the supine position.

Knee / Leg Support for CT
Permits reduction of lumbar spine curvature. Also useful for comfortable leg positioning in general.

Network Module:
For the connection to a local Ethernet network for communication with network printers, diagnostic
and therapy workstations, RIS systems and teleradiology routers.

Board of Directors:

Dr.Himadri Sikhor Das
Dr.Partha Hazarika
Dr.Chatra Dhar Choudhury
Dr. Pradeep Hatimota