Uneven distribution of radioactivity in the ribs, a diagnostic finding from radionuclide scanning, is usually associated with osteomyelitis, ischemic osteonecrosis, and bone tumors. 1. Osteomyelitis: It is a destructive inflammation of the bone that occurs due to bacterial infection. When stimulated by inflammation and producing inflammatory substances, uneven distribution will be detected by bone scanning. 2. Ischemic Osteonecrosis: When the blood supply to the bones is significantly reduced and then cannot be provided in time, osteonecrosis may occur, which leads to a series of pathological changes in the bones, and uneven distribution will be shown through bone scanning. 3. Bone tumors: mainly including benign tumors and malignant tumors, when the swelling gradually increases, presses on the surrounding tissues and metastasizes or spreads, uneven distribution will also be found through bone scanning. If the uneven distribution of rib radioactivity is found by rib scanning, there may be other reasons, so it is recommended to go to the regular hospital as soon as possible to find out the reasons and then carry out regular treatment.