The types of CT examination mainly include the following: 1) routine CT scanning of various parts of the body, that is, the simplest CT examination. 2) high-resolution scanning, which can reduce the layer thickness to 1-2mm, the resolution of routine scanning is significantly improved, and the edges of the tissues are sharpened, so that the bone or the fine structures in the lungs can be observed. 3) target scanning, which is to magnify the area of interest. 4) enhancement scan, which is to inject a contrast agent into the vessels and then perform a scan. 5) there are also some special scanning methods, such as angiography scanning, perfusion scanning, etc., which patients use needs to be decided according to the specific conditions of the patient. Scanning, that is, injecting contrast into the blood vessels and then scanning. 5, there are also some special scanning methods, such as angiography scanning, perfusion scanning, etc., which scanning methods need to be used according to the patient’s specific condition to decide.