To evaluate the clinical significance of optical coherence tomography (OCT) in interventional treatment of intracranial atherosclerotic stenosis (ICAS).

Stroke was the second leading cause of death worldwide and the leading cause of death in China in 2017. ICAS accounted for 10% to 15% of ischemic stroke in Western countries, and as much as 46.6%in Asia in 2009.

For patients with ICAS, the risk of stroke is highly related to the histopathology of atheromatous plaques. Therefore, characterizing the morphology and composition of plaques in ICAS may help to predict the risk of stroke occurrence and allow the adoption of preventive or therapeutic management to prevent such life-threatening events. OCT, with a resolution of 10μm, may provide more reliable information in characterizing atheromatous plagues.

This study aims to get a better insight into the value of OCT in evaluating the vessel wall structure and therefore guiding the interventional therapy of ICAS. In addition, the clinical and biological information will be included to achieve correlation analysis so as to get biomarkers subject to various plaque characteristics.

Inclusion Criteria:

• Symptomatic ICAS. Participants with ICAS with a transient ischaemic attack (TIA) or stroke attributable to the territory of the stenotic artery were defined as symptomatic. A TIA was defined as a transient episode of neurological dysfunction (focal weakness or language disturbance, transient monocular blindness, or required assistance in walking) caused by focal brain or retinal ischaemia that lasted for at least 10 minutes but resolved within 24 hours
• Stenotic degree ≥ 50%, measured by digital subtraction angiography
• The stenosis must located in at least one major intracranial artery (internal carotid artery, vertebral artery, middle cerebral artery, or basilar artery)

Exclusion Criteria:

• Arteriovenous Malformation
• Aneurysm

Adults (aged over 18) with symptomatic ICAS (≥ 50%) will be enrolled.