Diagnostic nuclear medicine began more than 50 years ago and has evolved into a major medical specialty. Its practitioners use low activity levels of radioactive materials in a safe way to gain information about health and disease. Small amounts of radioactive materials, known as radiopharmaceuticals, are intro- duced into the body by injection, swallowing, or inhalation. Different radiopharmaceuticals are used to study different parts of the body. These agents emit photons that can be detected externally by special cameras. These cameras produce images on film and/ or work in conjunction with computers to produce images of the body’s organs. An estimated 12–14 million nuclear medicine procedures are performed each year in the United States
