For patients with malignant tumors, early detection of bone metastases, as well as some malignant tumors such as prostate cancer, breast cancer and lung cancer patients before treatment and follow-up after treatment; for the diagnosis of unexplained bone pain (to exclude malignant bone tumors); in addition, for X-ray difficult to detect subtle fractures, such as fractures of ribs, finger bones, toes, can be early diagnosis; bone imaging can also observe the survival of transplanted bone Bone imaging can also observe the survival of bone graft and the follow-up of artificial joint replacement, etc. The greatest advantage is its high sensitivity. In most cases, bone imaging can detect bone metastases at an early stage, usually 3-6 months earlier than X-ray; because one imaging can understand the whole body skeleton, it can detect lesions beyond the scope of X-ray examination.