A bone scan, also known as skeletal scintigraphy, is a nuclear imaging test commonly used to determine whether cancer has spread to the bones from another area of the body (metastasized). The test can also be used to locate bone disease, infection, or injury, or to determine the source of unexplained pain. Bone scans can pick up abnormalities that don't show up on an X-ray.
A bone scan is not to be confused with a bone density scan (DEXA), which is a test to determine bone mineral density and diagnose osteoporosis.
How a bone scan works
A bone scan involves an injection of "tracers," which are very small amounts of radioactive material. As the tracer travels through your vein to the bones and organs, it collects in areas where there is injury, disease or disorder. As the tracer wears off, it emits radiation (less than one-half the amount of a CT scan). These "hot spots" are highlighted when an image is taken. This allows the radiologist to easily identify where the problem areas are.
While the initial injection may be uncomfortable, the bone scan itself is a painless procedure. The scan takes place with you lying on a table while the camera scans your body or parts of your body. The radiologist may wish to take some images immediately after the injection, and then again several hours later. If the radiologist requires closer examination of the bones, additional imaging may be needed with single-photon emission computerized tomography (SPECT). During a SPECT scan the camera rotates around your body, capturing bone images at different angles.
After the radiologist has reviewed the results and shared them with your doctor, additional testing may be indicated. Your doctor will go over your results with you and determine next steps.