PET/CT

Positron Emission Tomography, also called PET/CT, is a diagnostic examination where a radioactive substance is administered to the patient. This substance localizes to different areas of the body depending on changes in tissue metabolism, and is detected by the PET/CT scanner. The PET/CT scan allows doctors to evaluate a variety of diseases anywhere in the body, including the heart and brain.

For more information on this and other radiology procedures, please visit www.radiologyinfo.org.

WHO NEEDS PET/CT IMAGING?

PET/CT scans are most often used to detect cancer and to examine the effects of cancer therapy by characterizing biochemical changes in the cancer. This procedure can also determine whether a growth is malignant (cancerous) or benign (non-cancerous), evaluate the progression of disease, and 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.

HOW DO I PREPARE FOR PET/CT IMAGING?

Please do not eat or drink anything other than water for four hours prior to your PET/CT exam. Please drink one 10 oz glass of water two hours prior and a second 10 oz glass of water one hour prior to the exam. Please arrive 30 minutes prior to your exam in order to register. Most exams require a mild sedative; therefore, we request that ALL PET/CT patients bring someone with you to drive you home after the test. Please wear warm and comfortable clothing, and bring with you a list of any medications you are currently taking. You will be asked to refrain from exercising for 24 hours before your procedure.

What should I expect during this exam?

The PET/CT procedure typically lasts 2-3 hours. The amount of time involved to complete your scan will depend on the type of procedure your physician has requested. It begins with an injection of a small 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. The procedure may begin immediately upon injection, or may begin after an “uptake period,” depending on the type of examination being requested. You may be asked to rest in a quiet room and avoid significant movement or talking, which may alter the localization of the tracer.

The PET/CT scanner is very similar in size to a CT scanner and looks like a large doughnut. The patient is asked to lie comfortably on the imaging table while the scanner detects the concentration of the tracer within the body, and generates CT, PET, and fusion images by use of computer software.