Nuclear medicine imaging procedures are noninvasive and, with the exception of intravenous injections, are usually painless medical tests that help physicians diagnose and evaluate medical conditions. These imaging scans use radioactive molecules called radiopharmaceuticals or radiotracers that are compounds with a small chemical attached. In diagnostic imaging, the radioactive molecules attached to the chemical have low energy and is used to detect diseased or abnormal tissue.

Depending on the type of nuclear medicine exam, the radiotracer is either injected into the body, swallowed or inhaled as a gas and eventually accumulates in the organ or area of the body being examined. Radioactive emissions from the radiotracer are detected by a special camera or imaging device that produces pictures and provides molecular information.