Chest CT does not emit much radiation and poses little danger to the human body. Chest CT is chest X-ray computed tomography, which is to scan a certain thickness of the chest with X-ray beams, and then processed by computer to get the image of the scanning tomography. Chest CT mainly includes plain scanning, enhanced scanning and CT imaging. The X-ray output of the CT equipment is strictly controlled, and although there is a certain amount of radiation from CT examinations, the dose is very small, with a single chest CT radiation dose of about 8 mSv. In routine examinations, a smaller radiation dose does not significantly increase the incidence of cancer, nor does it threaten human health. Although a single CT radiation dose is very small, but long-term exposure to CT radiation, there is still a certain risk, especially in the CT room for a long time in the operation of the staff, the need to do the appropriate protection. Pregnant women, children, etc. should avoid CT examinations as much as possible.