PET Imaging What is PET Imaging? Positron Emission Tomography (PET) provides physicians with information about the body's chemistry not available through any other procedure. Unlike CT or MRI, which look at anatomy or body form, PET studies metabolic activity or body function. PET has been used primarily in cardiology, neurology, and oncology. In particular, it has been used to assess the benefit of coronary artery bypass surgery, identify causes of childhood seizures and adult dementia, and detect and grade tumors. How is the procedure performed? The patient lies on a table that slides into the middle of the scanner. Within the scanner are rings of detectors containing special crystals that produce light when struck by a gamma ray. The scanner's electronics record these detected gamma rays and map an image of the area where the radiopharmaceutical is located. Since the radiopharmaceutical contains a chemical commonly used by the body, PET enables the physician to see the location of the metabolic process. For example, glucose (or sugar, which the body uses to produces energy) combined with a radioisotope will show where glucose is being used in the brain, the heart muscle, or a growing tumor. What should I expect after the procedure? You can resume your normal baseline activities after the PET exam. More Information Link PET Imaging is available at the following locations: Seton Medical Center (San Mateo County) California Advanced Imaging at CPMC (San Francisco)