Vessel Wall and Perfusion Imaging in Intracranial Atherosclerosis

Detailed description: Title: Vessel wall and Perfusion Imaging in Intracranial Atherosclerosis Design: This is an prospective study that will study the characteristics of intracranial atherosclerotic plaque and the enhancement features of symptomatic ICAD during a mean follow-up of 1 year in symptomatic or asymtomatic patients with moderate to severe stenosis of middle cerebral artery(MCA). In the WASID trail,patients with at least 70% stenosis of a major intracranial artery had an increased risk of recurrent stroke. However,The degree of stenosis is no longer the single predictor of vulnerable atherosclerotic lesions. Vulnerable plaques are closely associated with stroke recurrence.With the development of neurologic imaging, HR-MRI has unique ability to provide information on plaque compositions, plaque burden and vulnerable features. Several recent investigations suggest that enhancement of intracranial plaque is associated with recurrent stroke. However, no corhort study has been performed. This prospective, multicenter trail will be conducted in China. Based on the previous work,participants will be divided into two groups :symtomatic ICAD and asymtomatic ICAD. Neurological examination and clinical sera testing will be performed at baseline, 1 month, 3 months, 6 months, and 12 months.The stroke incidence rate of asymptomatic ICAD and stroke recurrence rate of symptomatic ICAD will be recorded.