CT plain scan cannot clearly find out what kind of lesions exist in the cerebral blood vessels, but only the specific type of cerebrovascular disease.1. Cerebral infarction is shown as a low-density shadow on CT, and cerebral hemorrhage is shown as a high-density shadow on CT. If you want to further clarify the problems of cerebral vessels, you need to do CT arterial vascular imaging, also called CTA. This examination can clearly show all blood vessels by intravenous injection of contrast agent and then imaging, which can clarify whether there is atherosclerosis and plaque formation in the vessel wall, whether there is narrowing or occlusion in the vessel lumen, and clarify the degree of narrowing. As an important test to assess vascular function, it is also often performed prior to digital silhouette angiography.2. If the patient is indicated, further interventions can be done to implant stents. It can also help to screen patients for aneurysms, arteriovenous malformations, cavernous hemangiomas, and abnormal vascular network disease at the base of the brain.