Nuclear medicine is a branch or specialty of medicine and medical imaging that uses radioactive isotopes (radionuclides) and relies on the process of radioactive decay in the diagnosis and treatment of disease.
In nuclear medicine procedures, radionuclides are combined with other chemical compounds or pharmaceuticals to form radiopharmaceuticals.
These radiopharmaceuticals, once administered to the patient, can localize to specific organs or cellular receptors.
This property of radiopharmaceuticals allows nuclear medicine the ability to image the extent of a disease-process in the body, based on the cellular function and physiology, rather than relying on physical changes in the tissue anatomy.
In some diseases nuclear medicine studies can identify medical problems at an earlier stage than other diagnostic tests.
Treatment of disease, based on metabolism or uptake or binding of a ligand, may also be accomplished, similar to other areas of pharmacology.
However, radiopharmaceuticals rely on the tissue-destructive power of short-range ionizing radiation.