Thoracic spine flaky low density foci may be caused by osteoporosis, thoracic spine bone giant cell tumor, thoracic spine tuberculosis and other diseases. 1. Osteoporosis: when there is calcium deficiency in the body, it will affect the bone density, thus reducing the bone density, and such serious cases will have the phenomenon of osteoporosis, which may present the situation of thoracic vertebrae flaky low-density foci when taking radiographs through imaging. 2. Thoracic vertebral osteoblastoma: Thoracic vertebral osteoblastoma will destroy the bone quality, so when X-ray irradiation, there will be expansive osteolytic destruction, presenting soap bubble-like, and there may be thoracic vertebral flaky hypodense foci. 3. Thoracic spine tuberculosis: adult thoracic spine tuberculosis is mostly of vertebral body edge type, infection will cause destruction of vertebral body edge, necrosis of the foci of the cavity will appear, there will be pus, caseous material to fill in the X-ray will be manifested in the phenomenon of uneven density, there will be a thoracic spine flaky hypodense foci of the situation. Thoracic spine flaky hypodense foci may also be due to other reasons, it is recommended to ask the doctor in the hospital, the doctor will give the appropriate treatment according to the specific circumstances.