What is Nuclear Medicine ?
Nuclear Medicine involves the use of radioactive materials (isotopes , radioisotopes or radio pharmaceuticals) to diagnose or treat medical conditions. Very small amounts of radioactive materials (which have no harmful effect) allow “pictures” or “scans” of the area of the body that doctor needs to know more about. Sometimes larger amounts are used to treat cancer or certain thyroid disorders.
Used in proper amounts, radioactive materials have been shown to be extremely safe in adults and children and may even be used in pregnant women. The overall safety of Nuclear Medicine is unmatched by any other medical field. Studies of over 100,000 patients showed no ill effects after 15-20 years following treatment utilizing radioactive materials.
PET AND SPECT
PET : Positron Emission Topography.
SPECT : Single Photo Emission Computed Topography.
PET & SPECT :-
Shows blood flow by imaging trace amounts of radioisotopes. PET however can measure metabolism revealing how well the body is working. Use of radioactive tracer is well suited to studies of epilepsy, schizophrenia, Parkinson disease and stroke. Both PET and SPECT depict the distribution of blood into tissues, but PET does so with grater accuracy.
PET scanner watches the way tissue cells (eg brain cells) consume substances such a sugar (glucose). The substance is tagged with radioisotopes and brewed in a small low energy cyclotron. The isotope has a short half-life meaning it loses half of its radioactivity only within minutes or hours of being created. After injecting into the body, the radioactive solution emits positions wherever it flows. The positrons collide with electrons and the two annihilate each other releasing a burst of energy in the form of two gamma rays. These rays shoot in opposite direction and strike crystals in a ring of detectors located around the patient’s head or body causing the crystal to light up. A computer records the location of each flash and plots the source of radiation, translating that data into an image. By tracing the radioactive substance a doctor can pinpoint areas of abnormal brain activity or determine the health of cells.
Unlike PET, which specially requires a cyclotron on site, SPECT uses commercially available radioisotopes greatly reducing the cost of operation.
Nuclear Medicine Procedures
Most common scans a doctor might order and what they can do:
· Thyroid Uptakes and Scans are used to find over and under-active thyroid gland and to determine if lumps might be cancerous.
· Bone Scans find problems such as a tumor, infection and trauma sooner than x-rays and used to evaluate bone pain, injuries and many cancers.
· Heart scans are most often used to determine if chest pain is a result of heart disease and are also used to monitor the pumping function of the heart and detect recent heart attacks.
· Lung scans find blood clots in the lungs.
· Kidney scans find blockages to drainage or blood flow, tumor and infections of the kidney and can tell if high blood pressure is because of a kidney problem. Scans can also check for bladder reflux.
· Gallbladder scans help decide the need for surgery for abdominal pain.
· Stomach/Bowel bleeding can be located with nuclear medicine scans.
· Tumor/Abscess localization leads the way to finding the problem in difficult cases.
· Scintimammograms offer another way to look for cancers in the breast.
· Nuclear Medicine Therapy is the quickest, easiest, cheapest and most importantly the safest of all ways to treat overactive thyroid glands (hyperthyroidism). It is the best form of treatment for most cancers of the thyroid and may also be used for other cancers.