Coronary CTA refers to coronary CT angiography. It is mainly used to diagnose and exclude coronary artery disease, and to clarify the degree of stenosis of coronary arteries and the degree of plaque lesions. The principle of coronary CTA examination is to inject iodine contrast agent into the venous blood vessels, and then use multi-row CT to image the coronary arteries, and display the vascular condition through three-dimensional processing, which enables doctors to understand the degree of stenosis of the coronary arteries as well as the degree of lesions of coronary plaques. This test is commonly used in the clinic to diagnose and rule out coronary artery disease. Secondly, it is also used as a follow-up test for patients after bypass surgery. In addition, if a patient is allergic to iodine, he/she should not undergo coronary CTA examination, otherwise he/she is prone to adverse reactions such as rash, nausea, vomiting, dizziness and headache. When patients undergo coronary CTA examination, they need to actively cooperate with the doctor for diagnosis and treatment. If discomfort occurs during the examination, please inform the doctor in time to avoid delaying the condition.