Bone ECT examination is a radionuclide CT examination of bone, which belongs to the scope of nuclear medicine. The specific principle is to inject radionuclide drugs into the body, and the radionuclide will be distributed in the body with the blood, and the radionuclide will be concentrated in the parts with high metabolism and rich blood flow, and less in the parts with ischemia or inactive metabolism. The whole body is scanned and sampled by special CT to determine the blood flow and metabolism of bones, especially for the diagnosis of bone tumors, bone metastases and bone ischemic necrosis.