Reading a bone scan requires specific information. First you must be able to identify what part of the body has been scanned if there is no label on the scan. You will also need to know the orientation (left side/right side) of the scan since it can be done from the front side or back side of the patient. You will also need to know the time the scan was done to be able to determine the time it took the radioactive dye to reach the bones. There will be varying levels of brightness on the bone which indicate bone breakdown and rebuilding stages. These various stages of brightness will help diagnosis any problems.