Positron Emission Tomography, also called PET, is a diagnostic tool that produces images that demonstrate organ function. PET images are based on the detection of subatomic particles, specifically positrons.
Positrons are emitted from a radioactive substance administered to the patient and are ultimately detected by special crystals within the PET scanner. This information is then digitized to produce a 3-Dimensional image of the whole body or of a specific organ. With PET/CT, Computerized Tomography images are also obtained, which show detailed views of the structure of the body part being examined. The two types of images are “fused” by a computer into a set of pictures that shows both anatomical detail and function of the area being examined.
PET/CT scans are most often used to determine whether a growth is malignant (cancerous) or benign (non-cancerous), to evaluate the progression of disease and to assess the effects of clinical therapies. In addition, PET/CT is used to evaluate patients who have memory disorders such as Alzheimer’s Disease, seizure disorders that are not responsive to medical therapy and for the assessment of cardiovascular disease.
Resting Phase
The PET/CT procedure typically lasts 2-3 hours. It begins with an injection of a tiny amount of radioactive glucose (sugar) “tracer” solution that enables evaluation of glucose metabolism (function) in the body. There are no known side effects to this injection. Once injected, you will be asked to rest in a quiet room and avoid significant movement or talking, which may alter the localization of the tracer. The resting period lasts approximately 60 min.
Imaging Phase
The PET/CT scanner is very similar in size to a CT scanner and looks like a large doughnut. You will be asked to lie on an imaging table with a pillow positioned under your knees for additional comfort. It will take approximately 30-45 minutes for your scan and possibly longer depending on the type of scan your physician has requested. It is very important that you not move during the scan.
Scans generally take approximately 30 minutes. In some cases, more than one scan is required; you will be notified of the number of scans at the time of injection.