A bone scan looks for changes or abnormalities in the bones. It is also called a radionuclide scan, a scintigram or nuclear medicine scan.
A bone scan can look at a particular joint or bone. In cancer diagnosis, it is more usual to scan the whole body. The scan involves one injection but apart from that, it is painless.
The scan uses a large camera called a gamma camera. Gamma cameras pick up radioactivity. To have the scan, you first have a radioactive substance called a radionuclide injected into your bloodstream. You only need a very small amount of this radioactive substance – not enough to do you any harm. The radionuclide travels through the blood and collects in your bones. It tends to collect more in areas where there is a lot of activity in the bone. Activity means the bone is breaking down, or repairing itself. These areas of activity are picked out by the camera. Doctors call them hot spots. They show up as dark areas on the scan. Below is an example of a bone scan.