I. Overview Cerebrovascular disease is a common disease that seriously affects the health of our people, 75%-90% of which are ischemic cerebrovascular diseases, therefore, the prevention and treatment of cerebrovascular disease, especially ischemic cerebrovascular disease, is the top priority of our medical work. Epidemiological surveys have found that in 75% of transient ischemic attack (TIA) patients and 60% of cerebral infarction patients there are varying degrees of intracranial and extracranial cerebrovascular atherosclerotic plaques and stenosis. Stenosis of the extracranial segment of the internal carotid artery is one of the major causes of cerebral infarction. The main cause of arterial stenosis is atherosclerosis. Less common are arterial entrapment formation, arteritis, myofibrillar dysplasia, and radiation injury. Stenosis of the initial segment is the most common. The degree of internal carotid artery stenosis is one of the markers to distinguish the risk of stroke and its prognosis. China has entered an aging society and a large number of patients with cerebral atherosclerosis develop ischemic disease every year, but traditional drug therapy is not effective for plaques that have already formed. For most patients with atherosclerotic stenosis with no obvious symptoms, the stroke attack rate in the first year for patients with stenosis >75% is 2-5%. If the plaque is ulcerated, the stroke rate reaches 7.5% per year. For patients who present with symptoms, their stroke attack rate is much higher. Data from the North American Symptomatic Carotid Endarterectomy Collaborative Group study showed a 26% stroke rate within 2 years in patients with 70-99% symptomatic stenosis. Treatment Percutaneous Transluminal Angioplasty + Stenting (PTAS) is a new breakthrough in the treatment of intracranial and extracranial arterial stenosis. PTAS is significant because it can restore the diameter of the stenotic vessels, thus improving the blood supply to the brain and, more importantly, helping to prevent cerebral embolism caused by the detachment of atherosclerotic plaques. It is popular among patients and medical workers because of its minimally invasive and safe features. 1.Before and after stenting of carotid artery stenosis 2.Stenosis of the m1 segment of the right middle cerebral artery, pre-, mid- and post-operative angiographic performance Pre- and post-operative middle cerebral artery blood flow comparison