The need for angiography after CTA for stenosis depends on the condition of the patient: if the CTA result shows no stenosis, or if there is stenosis but the patient does not intend to intervene, angiography can be avoided; if the CTA shows that there is stenosis and the patient has a desire for intervention, angiography is needed. CTa is a non-invasive means of determining whether a vessel has stenosis, the degree of stenosis, wall calcification, etc. It has a high negative value, but it is not particularly accurate in determining the degree of stenosis, especially if the wall calcification is particularly heavy, which will affect the results. Angiography is an invasive method, which is more intuitive and accurate in determining the presence and extent of stenosis, and can be used for direct intervention if qualified. Whether CTa needs angiography or not needs to be judged by a professional doctor according to the condition, please follow the doctor’s instructions to avoid delaying the condition.