PET / CT
Positron Emission Tomography 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.
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 of these techniques is that the alteration in structure or anatomy that occurs with disease can be visualized by the technique. Biochemical processes which are altered by disease may occur before there is a CT or MR-visible change in gross anatomy. PET is an imaging technique that is used to visualize some of these metabolic alterations. Even in early disease where there is no gross structural abnormality visible on CT or MRI, the PET scan may be able to show a biochemical change.
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 the body, most commonly glucose sugar. Other compounds similar to glucose, water, ammonia, and certain drugs may be used. The radioactive tracer is injected by vein, and a specially designed positron scanner images how the body processes the tracer. PET has been in clinical use since the early 1990’s.
PET/CT is the state-of-the-art standard for performing PET, which includes a superimposed CT evaluation which shortens the amount of time the patient spends on the table, and improves the accuracy of the examination by mapping out more precisely any areas of abnormality.