FOCAL CT BRAIN LESIONS

RING ENHANCING LESIONS
(CT)
Primary brain tumor (glioblastoma) – irregular thick ring
Metastasis (especially if on ChemTx),
Abscess – ring is more smooth and regular – thinner on medial (WM) side ,
Multiple sclerosis – in white matter,
Resolving hematoma – 10-21 days – usually has perilesional lucency
Tuberculoma – associated extracranial TB often found – irregular ring
Radiation necrosis – 9 months-3 years after Rtx > 4000 rads
Postoperative change (at edges of resection)
Aneurysm – due to intraluminal thrombus

HYPERDENSE LESION WITHOUT CONTRAST
Meningioma – 20% also show hyperostosis – 2/3 show peritumoral edema
Lymphoma (small round blue-cell tumor – densely cellular) – primary is usually intraaxial – secondary is often extraaxial
Metastasis – Melanoma/Renal cell Ca/Choriocarcinoma/Thyroid Medulloblastoma (small round blue-cell tumor – densely cellular) Glioblastoma Ependymoma Colloid cyst (inspissated mucus)
Hemorrhage (acute) / hemorrhagic infarct
Craniopharyngioma
Germinoma (pineal and suprasellar)

MULTIPLE ENHANCING LESIONS
Hematogenous: Metastases – 45 -55% of CNS mets multiple – >2cm often cavitate – usually near gray-white junction (peripheral > central)
Lymphoma – usually deeper, periventricular, may be rings in AIDS Disseminated infection (multiple abscesses)
Multifocal infarction Inflammatory/Unknown Etiology: Multiple Sclerosis (white matter lesions)
Vasculitis Hypertensive Crisis/Ecclampsia Inherited Mass Lesions/Neoplasms: Hemangioblastoma (von Hippel-Lindau) Arteriovenous malformations (cavernous hemangioma >> AVM)
Meningiomas – 4% are multiple (some with NF-2, most without)
Multicentric gliomas – 5% of all gliomas Tuberous sclerosis Neurofibromatosis (both types – NF1 (von Recklinhausen) and NF2 (MISME)

GYRAL ENHANCEMENT: * Ischemia/Infarction (incl. seizures, migraines, etc.) * Cerebritis/Encephalitis (e.g. Herpes) Meningeal carcinomatosis (carcinomatous meningitis) Meningitis – chronic > acute AVM Cortical vein thrombosis Lymphoma Meningioangiomatosis (NF2)

Advertisements
This entry was posted in Uncategorized and tagged .

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s