Clinically, CT examination of the lung mainly refers to CT examination of the chest, including the lung, bronchus, thorax, esophagus, heart and ribs and sternum, so CT examination of the lung can detect rib lesions, including fractures, bone tumor metastases, lung tumor metastases and changes in bone density. Especially for changes in bone proliferation and degeneration such as thoracic spine, CT values can detect changes related to bone density while suggesting whether the changes in that bone are physiological or pathological. Bone metastasis of lung cancer can see the erosion and destruction of the rib bone, suggesting that there are generally considered other lesions metastasized to the rib bone and destroyed the bone tissue of the rib bone leading to pathological changes, so CT of the lung is able to examine the rib bone.