Inflammatory nodular foci in the dorsal segment of the upper and lower lobes of both lungs are mostly considered as inflammatory nodules, pulmonary nodular disease, lung cancer, lung metastases, etc. 1. Inflammatory nodules: Inflammatory exudation of lung tissue caused by various pathogen infections, which can be manifested as multiple nodular shadows on imaging, especially certain viral pneumonia. 2. Pulmonary nodular disease: a kind of granulomatous disease of unknown etiology that involves multiple systems of the whole body, and is prevalent in the lungs and lymph nodes. On imaging, it can be manifested as multiple nodular shadows in the lungs and enlarged lymph nodes, which can lead to severe pulmonary fibrosis as the disease progresses. 3. Lung cancer: the cancer can spread in the lungs and form multiple nodular lesions in the lungs, especially lung adenocarcinoma is easy to spread in the lungs through the airways. 4. Lung metastases: malignant tumors in other parts of the body can metastasize to the lungs and form metastatic foci, which are mostly multiple nodular foci, such as osteosarcoma, soft tissue sarcoma, cervical cancer and so on. Nodular foci in the upper and lower lobes of both lungs can also be seen in other causes, and it is recommended that the patients go to the hospital as soon as possible, so as to avoid delaying the condition.