Nuclear medicine is a medical specialty that uses safe and painless techniques to image the body and treat disease. Nuclear medicine imaging is unique in that it documents organ function and structure, in contrast to diagnostic radiology, which is based upon anatomy. This type of imaging involves the IV administration of a small amount of radioactive material called "Tracers." Nuclear medicine imaging procedures often identify abnormalities very early in the progression of a disease, long before some medical problems are apparent with other diagnostic tests. This early detection allows a disease to be treated early in its course when there may be a more successful prognosis. Nuclear medicine uses very small amounts of radioactive materials or radiopharmaceuticals to diagnose and treat disease. Radiopharmaceuticals are substances that are attracted to specific organs, bones or tissues. The radiopharmaceuticals used in nuclear medicine emit gamma rays that can be detected externally by special types of cameras. These cameras work in conjunction with computers used to form images that provide data and information about the area of the body being imaged. The amount of radiation from a nuclear medicine procedure is comparable to that received during a diagnostic X-ray.