As CT instruments become more and more advanced, lung spiral CT once a scan, radiation is about 5-10mSv, and a normal person within 1 year as long as less than about 100mSv can be, so do a lung spiral CT, radiation is far below the national safety value, patients do not have to worry too much. Spiral CT of the lungs, if used properly within the scope of medical use, has far more advantages than disadvantages for patients, and can detect many lung diseases in patients, which is unmatched by other imaging methods. Patients who have problems with their lungs often need a lung CT to make a clear diagnosis, which can determine whether the patient has inflammation, tuberculosis, tumors or other lesions in the lungs.