7. Nuclear Medicine

The first step in any nuclear medicine diagnostic imaging study involves the administration of a radiopharmaceutical to a patient. A radiopharmaceutical is a chemical combination of a radionuclide and a pharmaceutical (Fig. 7.1). A radionuclide is an unstable isotope of an element which emits radiation to achieve stability. When this radiation is in the form of gamma rays, it can be detected by a nuclear medicine gamma camera (Fig. 7.2). A pharmaceutical is a compound which localizes in normal or diseased tissue. A nuclear medicine image depends on the physiologic distribution of the pharmaceutical which is administered.