Nuclear medicine uses small amounts of radioactive substances to image specific body parts/organs and treat disease. Nuclear materials are swallowed or injected into the bloodstream, where the radioactive tracers then collect in the region of interest. Images are created by positioning detectors near the patient to collect radiation emitted and transform this energy into a picture.
The are a variety of nuclear medicine imaging techniques, carrying names such as positron emission tomography (PET), single photon emission computed tomography (SPECT), cardiovascular imaging or bone scanning. These are used to detect cancers or the spread of cancer, fractures which cannot be seen on traditional x-rays and evaluating the functioning of major organs such as the kidneys, lungs, stomach and thyroid glands.
The radioactive substances that are used do not harm the body because they decay quickly and emit very low levels of radiation. The body quickly eliminates the radioisotope through the kidneys and liver levels.