Bronchitis is not necessarily detected by CT, and lung cancer can be detected by CT. Bronchitis is caused by microbial infection, physical or chemical irritation and other factors, and patients will have symptoms such as coughing and sputum. Generally, X-ray examination, blood test, sputum culture and lung ventilation function can diagnose whether there is bronchitis or not, CT may not be able to detect it, and we cannot only rely on CT performance for diagnosis, but need to combine with clinical history and clinical symptoms to make comprehensive judgment. Lung cancer is a malignant tumor originated from bronchial mucosa or glands in the lungs. Lung cancer can be detected through imaging examination, which can understand the location and scope of lung cancer lesions, and can roughly differentiate between benign and malignant, and it is an important means for the diagnosis of lung cancer at present. However, if you want to diagnose lung cancer, you need to carry out pathologic examination, which is the gold standard for the diagnosis of lung cancer. If you want to know whether you are suffering from bronchitis and lung cancer, it is recommended that you go to regular hospitals and have relevant examinations, so as to achieve early detection and early treatment.