Nuclear medicine is a specialized area of radiology that uses very small amounts of radioactive materials, or radiopharmaceuticals, to examine organ function and structure. Nuclear medicine imaging is a combination of many different disciplines, including chemistry, physics, mathematics, computer technology, and medicine. This branch of radiology is often used to help diagnose and treat abnormalities very early in the progression of a disease, such as thyroid cancer.
A tiny amount of a radioactive substance is used during the procedure to assist in the examination. The radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is absorbed by body tissue.
By measuring the behavior of the radionuclide in the body during a nuclear scan, the doctor can assess and diagnose various conditions, such as tumors, abscesses, hematomas, organ enlargement, or cysts. A nuclear scan may also be used to assess organ function and blood circulation.
An intravenous injection of a radioisotope is necessary for the majority of Nuclear Medicine exams. Sometimes there are delays between the injection and the imaging in order to give the body time to absorb the radioisotope and become visible on a special camera. Some exams require a consultation and record of present medications prior to scheduling.