1.What is intracranial vascular stenting? It is a treatment method to introduce a small intracranial vascular stent into the middle cerebral artery or basilar artery through a microcatheter to achieve the purpose of rebuilding the blood flow in a cis-grade manner. Because of the thin intracranial vessels and abundant penetrating branches, it is technically difficult. 2.What is intracranial balloon dilation and angioplasty? In patients with intracranial artery stenosis who have difficulty in introducing stents, balloon dilatation of the stenosed vessels is used to improve blood flow. 3.What patients need stenting of intracranial arteries (middle cerebral artery, basilar artery)? ① Symptomatic intracranial artery stenosis >50%. ②The distal stenosis is normal, the length of the lesioned vessel in the posterior circulation is <20 mm, and the length of the lesioned vessel in the anterior circulation is <15 mm. (③) Residual stenosis >50% after acute arterial thrombolysis. ④Recurrent clinical episodes of neurological dysfunction consistent with the area supplied by the stenotic vessel. ⑤ No serious systemic diseases, such as heart, liver and kidney failure. 4.Which patients are not suitable for intracranial artery (middle cerebral artery, basilar artery) stenting? ①Serious systemic diseases. ②Severe neurological dysfunction left after infarction. ③Asymptomatic or mild symptoms with effective drug control. ④Vessel diameter of the stenotic segment is less than 2mm, and the stenotic segment is extremely angular. ⑤ unexplained lesion (early arteritis, MoyaMoya , disease congenital dysplasia), diffuse stenosis of intracranial arteries. (6) Stenosis involving important penetrating branches. (vii) Within 2 weeks of cerebral infarction and within 2 weeks of myocardial infarction.