Angiography and cta are both tests used to determine the presence or absence of stenosis and the degree of stenosis of blood vessels, and both require the injection of contrast medium, which carries the risk of allergy and other risks, which is the same in this regard; angiography requires arterial puncture, while cta does not, and the risk of arterial puncture is relatively greater, so the hazards of angiography are even greater. Angiography is an invasive examination in which a catheter is sent through the radial artery, femoral artery or brachial artery into the entrance of the blood vessel to be examined, injected with contrast medium, and photographed in different directions to clarify whether the blood vessel is stenotic or not and the degree of stenosis, etc. Inadequate operation may lead to infection of the puncture site and damage of the blood vessel in the process of puncture, etc. Cta is performed in the veins of the upper limbs. Cta is a non-invasive procedure that involves injecting a contrast medium into the veins of the upper extremities and then performing a CT scan, and then the doctor analyzes the results of the scan, performs a vascular reconstruction, and draws conclusions, which is non-invasive and doesn’t require a puncture of the arteries. If you need to identify vascular lesions, please go to a specialized hospital and the doctor will choose the test according to the specific situation, so please follow the doctor’s instructions.