脑卒中是国人第一位致死性疾病。颅内、外颈动脉、主动脉弓的管壁粥样硬化(AS)易损斑块破裂引发的血栓栓塞是缺血性卒中的主要致病因素。目前临床上仍以测定管腔狭窄程度来评价AS病变的严重性。然而近来研究显示，约有20%以上轻度狭窄的颈动脉存在AS易损斑块。因此，有必要对动脉管壁进行直接成像来评价AS斑块的稳定性。然而，除颅外颈动脉外，目前还没有可靠的成像技术识别颅内颈动脉和主动脉弓管壁易损斑块。本研究将以最新MR成像技术(SNAP)为基础，拟开发一种只需一次采集即可同时进行非增强MRA和管壁易损斑块(斑块内出血)成像的快速、高分辨率MR成像序列，应用本研究组设计的新型36通道神经血管线圈，对缺血性卒中患者脑组织上游血管(自主动脉弓至颅内颈动脉）全景进行成像，探索易损斑块的分布规律及其与脑缺血灶的相关性。本研究将为缺血性卒中责任病变的诊断提供一站式MR成像方法，从而有效指导临床治疗，降低复发风险。

Stroke has become the first cause of death in China. The disruption of atherosclerotic vulnerable plaque with subsequent thromboembli at upstream vascular beds of brain, such as intracranial and extracranial carotid arteries, and aortic arch is believed to be major etiology for ischemic stroke. Currently, measuring luminal stenosis by various angiographic approaches is still the major strategy for assessment of the severity of atherosclerotic disease. However, a number of recent studies have shown that more than 20% of symptomatic carotid arteries with lower grade stenosis developed vulnerable plaques. As such, to direct image the vulnerable plaques at arterial vessel wall is strongly suggested. There are no appropriate imaging techniques developed for plaque imaging of intracranial carotid artery and aortic arch, except for extracranial carotid arteries. This study sought to develop a new MR imaging sequence to simultaneously obtain the non-contrast angiography and intraplaque hemorrhage imaging for the upstream arterial territories (from aortic arch to intracranial carotid artery). This imaging sequence is based on a most recent imaging technique "Simultaneous Non-contrast Angiography and intraPlaque hemorrhage (SNAP) imaging" which is developed by our group. In this study, by using the new developed imaging technique and a new designed and optimized 36-channel neurovascular coil by our group, we plan to investigate the prevalence of vulnerable plaques at the upstream vascular beds of brain. The relationship of vulnerable plaques at these vascular beds with cerebral ischemic lesions will be also evaluated. By doing this study, a 'one-stop shop' imaging protocol to detect the culprit lesions of patients with ischemic stroke will be established. To acquire the information of plaque vulnerability at these vascular beds by utilizing the new developed imaging technique will be helpful to guide the therapy and prevent the recurrence of future cerebrovascular events.