The CTA test is performed mainly by injecting a drug into a vein and scanning it with CT as it passes through the arteries of the blood vessels, and the resulting images are computerized to image the arteries, which is the approximate process of CTA testing. Before the procedure, it is important to explain to the patient that the injected contrast agent drug may have an effect on renal function. CTA is mainly for arterial vascular diseases, which can give doctors and patients a three-dimensional image and can directly see what the lesions and blood vessels are. It is a very important test in vascular surgery, which can clarify the location of the lesion and the degree of stenosis before surgery, and give some hints on the treatment method and surgical entry. Therefore, CTA is a very common test in vascular surgery.