A bone scan is a test that detects areas of increased or decreased bone metabolism (turnover). The test is performed to identify abnormal processes involving the bone such as tumor, infection, or fracture.

A radiotracer (a bone-seeking radioactive material) is injected into vein, so it travels through the bloodstream. As the material wears away, it gives off radiation. This radiation is detected by a camera that slowly scans your body. The camera takes pictures of how much radiotracer collects in the bones.

If a bone scan is done to see if you have a bone infection, images will be taken shortly after the radioactive material is injected, as well as 3 to 4 hours later, when it has collected in the bones. This is called a 3-phase bone scan.

To evaluate metastatic bone disease, images are taken only after the 3 to 4 hour delay.

The scanning part of the test will last about 1 hour and may require you to change positions.

You must remove jewelry and other metal objects. You may be asked to wear a hospital gown.

There is a small amount of pain when the needle is inserted. During the scan there is no pain. You must remain still during the examination, and you will be instructed when to change positions by the technologist.

You may experience some discomfort due to lying still for a prolonged period of time.