A positron emission tomography (PET) scan is a unique noninvasive nuclear imaging technique that produces three-dimensional images of the living heart, brain or other organs. PET scans are often used in the diagnosis and management of cancers, certain brain disorders and heart disease. It is especially helpful to determine the presence and extent of coronary artery disease (CAD) or damage to the heart after a heart attack.

If the test is conducted after mild exercise (a stress test), it is similar to other nuclear stress tests, except that it has two major advantages. First, the images are less likely to be distorted by parts of the patient’s body (large breasts, obesity etc.), so abnormal results are more reliable, especially when combined with conventional computed tomography (CT) scanning. Second, it is an excellent tool for determining whether portions of the heart muscle are still viable (living and functioning) after a heart attack or other event in which there is a lack of oxygen-rich blood to the heart muscle.

However, PET scanning is not as readily available as more conventional nuclear imaging because of its greater cost and the need for a cyclotron device, which produces necessary isotopes on site. In recent years, the cost of PET scanning has dropped due to increased availability of isotopes and scanners. Also, in some centers, PET scanners have been combined into the same unit with CT scanners, thus reducing the time needed to conduct the test.

Before the test, people are encouraged to:

During the test, they may feel the needle prick when an intravenous (I.V.) line is inserted in their arm to administer a small amount of radioactive material. Otherwise, the test is painless, and the amount of radioactivity is roughly the same as patients are exposed to during a CT scan. The test takes at least an hour to complete. Afterward, patients may drive themselves home and go about their usual activities, drinking plenty of water to flush the radioactive material from their body.