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Diagnostic Imaging Studies

Positron Emission Tomography (PET) Scan

How it works: PET scans create images based on the metabolic activity of cells in the body. A small amount of radiolabeled glucose is injected into the bloodstream. The glucose is taken up and metabolized by the tissues. The PET scanner reads the signal emitted by the radiolabeled material to produce computer-generated images of your body. Since cancer cells metabolize more glucose than normal cells, they "light up" more brightly on the PET scans and can help your doctor pinpoint your disease.

PET scans may also be helpful in differentiating benign masses, such as cysts, from cancerous tumors. They may also help to identify small metastases to the liver and other surrounding organs that do not show up on CT or MRI scans. PET scans are now often done in conjunction with CT scans to provide a complete image of the body that including both molecular (PET) and anatomical (CT) visual information.

What to expect: Before the test, you will be given an injection of the radioactive substance and asked to rest for about an hour. Similar to a CT scan, you will then be asked to lie on a bed which will move slowly through a donut shaped ring. As with all scans, it is important that you do not move during the test. The entire PET scan process, from injection to completion, can take up to 3 hours.