Low-dose spiral CT does not have much radiation. Low-dose spiral CT means that the scanning range is small and the radiation dose is small when CT scanning is performed in this way. Compared with ordinary CT scanning, the radiation of low-dose spiral CT is smaller, but the quality of the imaging will be poorer than that of ordinary CT scanning, however, the low-dose spiral CT examination can also find very small lesions, generally 5mm lesions can be found. Generally, low-dose spiral CT examination can be used for unit-organized health checkups, census of high-risk patients and lung cancer screening, and it can also be used for short-term patients who need multiple re-examinations and long-term follow-up observation. Doctors need to choose the specific examination method according to the patient’s condition, if you need to diagnose the disease more accurately, it is recommended that the patient choose conventional CT examination.