Nuclear medicine uses a small amount of radioactive tracers to diagnose and treat a variety of diseases. Differing from X-ray, which demonstrates anatomy or structure, nuclear medicine provides information on how parts of the body function. The radioactive tracers are administered by IV injection, inhaled through a nebulizer or swallowed. The radioactive tracers are attracted to specific organs, bones or tissues in the body. The radioactive tracers will eventually concentrate in the organ of interest. A special camera called a gamma detector will be positioned close to the part of the body that is being scanned. The information is then sent to a computer that processes and analyzes the amount and distribution of radioactive tracers in your body. Depending on the test, the scan may be performed immediately or after a few days. Some scans may require multiple visits.
Nuclear medicine is safe and painless. The radioactive tracers used are quickly eliminated from the body through its natural functions. The dose of radiation is very small and the radioactive tracers lose their activity very quickly. Reactions to the radioactive tracers are rare. However, prior to the administration of any radioactive tracer, it is important to tell your physician and the nuclear medicine technologist if you are pregnant or nursing. Special precautions or a delay in performing your procedure may be necessary. You may be instructed to take special precautions after urinating, such as flushing the toilet twice and thoroughly washing your hands. You should also drink plenty of water after the exam.
Nuclear medicine scans can study any organ in the body, including the bloodstream. The most common tests are scans of the bones, heart, lungs, kidneys, gallbladder and thyroid. The purpose of these exams is to analyze kidney function; visualize heart blood flow and function; scan lungs for pulmonary embolism; evaluate the gallbladder for inflammation (cholecystitis) or poor function; evaluate bones for fractures, infection, arthritis and tumors; determine the presence or spread of cancer in various parts of the body; identify location of bleeding in the bowel; confirm and identify the location of infection; measure thyroid function in patients with symptoms of overactive or underactive thyroid; and localize abnormal lymph nodes before surgery in patients with breast cancer or melanoma.
Preparing for a Nuclear Medicine Test
Various procedures have different protocols, and therefore, will require specific instructions. It is likely that you will be advised not to consume food or drink for at least 4 hours prior to your appointment. If you are having a renal (kidney) function test, plan to drink plenty of water in advance of the procedure.