AcoArt sICAS: DCB in the Treatment of Symptomatic Intracranial Atherosclerotic Stenosis

Inclusion Criteria: * 18 to 80 years of age; * Patients with symptomatic intracranial atherosclerotic stenosis; * Patients with intracranial arterial de novo stenosis confirmed by digital subtraction angiography (DSA); * Confirmed by DSA，the diameter of the target vessel is between 2.5mm-4.5mm ; according to WASID method, the degree of stenosis of the target lesion is 70%-99%; * Baseline mRS score ≤2; * Voluntarily participate in this study and sign the informed consent form. Exclusion Criteria: * Patients with stroke within 2 weeks before procedure; * Patients with stroke caused by perforating artery occlusion; * Any history of brain parenchymal or other intracranial subarachnoid, subdural or extradural hemorrhage in the past 30 days; * Those who have received thrombolysis within 24 hours before procedure; * Deterioration of neurological function within 24 hours before procedure (defined as NIHSS score increased by ≥ 4 points over the baseline); * The vascular path showed in angiography is so tortuous that it is difficult to advance catheters to the target lesion or retrieve; * Lesions that investigators believe are not suitable for stenting; * Patients with thrombus in target vessel; * In addition to the target lesion, there are still other de novo lesion or ISR lesion with more than 70% diameter stenosis in intracranial arteries that need to be treated at the same time; * After endovascular treatment of the target lesion, there is still a stenosis of more than 50% in th…