Coronary CTA is a more commonly used test to confirm the severity of coronary artery disease and stenosis. Coronary angiography is a minimally invasive test to determine the severity of coronary artery disease and stenosis, and is more accurate than coronary CTA. To have a coronary angiogram, you need to be hospitalized and it is more expensive than a coronary CT. If a patient has a coronary CTA and finds that the vascular calcification is more severe, it is difficult to further assess the specific degree of stenosis of the vessel, and further coronary angiography is needed to clarify the diagnosis.