Nuclear medicine uses very small, safe amounts of radioactive materials, or tracers, to help diagnose and treat a variety of diseases. Depending on the type of exam, these tracers are either swallowed or injected into your body, where they emit energy in the form of gamma rays. You then are scanned with a special gamma camera, which detects the rays and produces computer images of organs and tissues.
There are nearly 100 different types of nuclear imaging procedures, including PET scans , bone scans, and heart scans. Unlike other imaging procedures, which focus on structural appearance, nuclear imaging scans show how an organ, tissue, or bone functions. As a result, nuclear imaging often can identify potential problems long before they can be detected by other imaging methods.