Abnormal radioactive concentrations are mainly seen in ECT of bone or PET-CT of the whole body. Both of these tests are radionuclide CT scans, in which radionuclides are taken, circulated through the bloodstream to the whole body, and CT is used to detect the distribution of radionuclides. When the local blood circulation is rich, it shows abnormal concentration of radionuclides, which can detect local lesions, especially tumor lesions or areas with very high bone metabolism, and make a diagnosis of the disease. It is often suggested that the local blood circulation is rich, that is, the bone metabolism is rich, mainly seen in tumor diseases, because tumor is a rapid growth abnormal differentiation disease, is a kind of unregulated rapid growth, resulting in local vascular proliferation, appearing corresponding phenomenon of radioactive concentration.