Bone scan

Bone scan (radionuclide scanning) – A technique for creating
images of bones on a computer screen or on film. Prior to
the procedure, a very small amount of radioactive dye is
injected into the bloodstream. The dye collects in the bones,
particularly in abnormal areas of the bones, and is detected
by a scanner. This test detects blood flow to the bone and cell
activity within the bone, and can show abnormalities in these
processes that may aid diagnosis.