If you have unexplained bone pain, a bone scan might help determine the cause. The test is very sensitive to any difference in bone metabolism. The ability to scan the entire skeleton makes a bone scan very helpful in diagnosing a wide range of bone disorders, including:
Paget's disease of bone
Cancer originating in bone
Cancer that has metastasized to bone from a different site
Infection of the joints, joint replacements or bones (osteomyelitis)
Impaired blood supply to bones or death of bone tissue (avascular necrosis)
It's used to diagnose bone disease and bone cancer, or cancer spread to the bone.