Bone scanning is extremely sensitive at detecting subtle stress fractures or bone tumours when they are invisible on plain x-rays. It is particularly helpful when it is unclear exactly where the problem is in the skeleton. It offers the ability to take a picture of the entire skeleton and light up the area where the problem appears to originate.
In order to perform a bone scan, a radioactive chemical is injected into the bloodstream. This chemical attaches itself to parts of bone that are undergoing rapid change. After a gamma camera scans the area, these parts show up as dark areas on the film. Once the affected area is identified, additional tests such as a plain x-ray or CT scan may be used for further evaluation of the affected structures. A bone scan requires the patient to have an injection of the radioactive chemical in the morning and to return approximately 4 hours later for the images to be taken. The first part takes approximately 15 minutes and the second part approximately 30 minutes.