Radionuclide imaging is a technique that allows physicians to obtain clear images of various parts of the body. To obtain the images generated in this technique, tiny amounts of radioactive materials called “tracers” are introduced into the patient’s body. The tracers emit a type of energy called gamma rays, which are detected by special devices.

For example, a PET scan (positron emission tomography) uses machines called photomultiplier-scintillator detectors to detect the gamma rays. Another test, the SPECT scan (single-photon emission computed tomography), uses a gamma camera to detect the energy. The information detected and recorded by these machines is then analyzed and reconstructed by computers to create clear images of the target area.

For most people, the tracer is harmless and is flushed from the body after the test. However, some people should avoid radionuclide imaging, including women who are pregnant or breastfeeding. The test itself can generate radiation that is potentially harmful to a developing fetus, and the tracer that is used can be passed to an infant through breast milk. Therefore, a woman should inform her physician if she is pregnant or nursing before undergoing these tests.

Radionuclide imaging may be used to assess several conditions that women may develop, including breast and reproductive cancers, bone disease or fractures, arthritis and disorders of the urinary tract.