Angiography is an auxiliary examination to clarify vascular lesions. It is an injection of contrast into the blood vessels, which can display the dynamic images of the vessels very clearly under the X-ray machine, and clarify the lesion site, length, degree of stenosis and morphological changes of the vessels. Contrast is often an important adjunct to interventional treatment and is also the most important step in the interventional process. If stenosis, occlusion, or even aneurysmal-like changes in the lesion occur during the contrast procedure, interventional treatment can be performed directly after contrast. CT angiography is commonly used to inject the contrast agent into the whole body through a vein and to visualize the blood vessels in the arterial or venous phase at different times, and the 3D reconstruction of the blood vessels can be performed through CT software, which can show the location and nature of the vascular lesions more clearly and intuitively.