Intracranial atherosclerotic disease is the most common cause of ischemic stroke in Asia, also in China. Currently, despite vascular recanalization therapy, statins are one of the main drug choices for treating atherosclerotic plaque. High resolution magnetic resonance imaging (HRMRI) can accurately assess the status of intracranial and extracranial arterial plaque, and has high consistency with histopathology. Thus, HRMRI technology has been widely used to monitor the efficacy of drug treatment for atherosclerotic plaque in clinical trials or practice. As a non-invasive technique, HRMRI make it possible to assess the morphologic characteristics of vascular wall and plaque composition of intracranial artery in vivo. It can quantitative analysis including components such as lipid-rich necrotic core, fiber cap thickness, intra-plaque hemorrhage, calcification, etc. Therefore, it is crucial for evaluating the etiology of ischemic stroke and developing secondary prevention strategies. At present, there is a lack of large-scale and prospective study to evaluate the etiology of ischemic stroke including cryptogenic stroke based on HRMRI. In this context, this study aims to establish a multi center HRMRI database of intracranial arteries among Chinese patients with ischemic stroke.