Blood vessel blockage can be examined by color ultrasound, enhanced CT and angiography. 1. Color ultrasound: It is a non-invasive examination method, which can observe the blood flow of blood vessels and understand the degree of blood vessel blockage, and is suitable for the screening of blood vessel blockage and can be observed dynamically. 2. Enhanced CT: CT scanning is performed after injecting the contrast agent, which can show the traveling of blood vessels and assess the degree of vascular blockage. 3. Angiography: also need to inject contrast agent, and then under the monitor to observe the blockage of blood vessels, is a more accurate clinical examination, but is an invasive way of examination, the examination process will cause some damage to the patient. Patients with vascular blockage should choose the appropriate examination method under the guidance of physicians to assess the severity of vascular blockage.