PET
(Positron
Emission
Tomography)
is a nuclear medicine procedure that produces pictures of the body’s
biological functions. This is important because functional change often
predates structural change in tissues, such as tissue metabolism and
physiologic functions.
How
Does PET Work?
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 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
1990's.
