Positron Emission Tomography (PET) is a non invasive, diagnostic imaging technique for measuring the metabolic activity of cells in the human body. It is useful clinically in patients with certain conditions affecting the brain and the heart as well as in patients with certain types of cancer. The field of PET has been emerging into clinical diagnostic medicine and is approved by many insurance carriers for coverage.
PET is unique because it produces images of the body’s basic biochemistry or function. Traditional diagnostic techniques, such as x-rays, CT scans, or MRI, produce images of the body’s anatomy or structure. The premise with these techniques is that the change in structure or anatomy that occurs with disease can be seen. Biochemical processes are also altered with disease and may occur before there is a change in gross anatomy. PET is an imaging technique that is used to visualize some of these processes that change. Even in diseases, such as Alzheimer’s disease, where there is no gross structural abnormality, PET is able to show a biochemical change. PET is a very useful addition to the clinician’s diagnostic toolbox, providing significant advances to traditional diagnostic methods.
A PET Scan is a simple procedure. It involves the use of a small amount of a radioactive material, similar to what is used in other nuclear medicine procedures. The radioactivity is attached or tagged to a compound that is familiar to your body. Compounds similar to glucose, water, ammonia, and certain drugs may be used. The radioactive drug is administered to the patient, usually by injection, and a specially designed PET scanner images how the body processes the drug. PET has been in clinical use since the early 1990s.
PET has been shown to be useful to physicians in the care of patients with many types of diseases. Specifically, PET is useful in the diagnosis and management of patients cancer, with certain neurologic disorders, and with heart disease.