Morphologic Evolution and Remodeling of Intracranial Atherosclerosis: A Longitudinal Study by 3D-rotational Angiography

Inclusion Criteria: 1. Patient is 30 to 85 years of age, inclusive. 2. Patients who have an acute infarct in diffusion-weighted MRI compatible with artery-to-artery thrombo-embolism and a relevant intracranial atherosclerotic stenosis ≥60%. 3. Patient who has no contra-indication for the proposed imaging tests. 4. Patient understands the purpose and requirements of the study, and has provided an informed consent. Exclusion Criteria: Patient with any of the following conditions would be excluded: 1. Stroke etiology uncertain or unrelated to intracranial atherosclerosis, such as cardioembolism, Moyamoya disease, small vessel disease or primary angiitis of CNS. 2. A tandem stenosis \>50% at extra-cranial internal carotid artery. 3. Bleeding propensity: active peptic ulcer disease, major systemic hemorrhage within 30 days, thrombocytopenia (platelets \<100 x 109/L), coagulopathy (INR \>1.5). 4. A medical condition that would not allow the patient to adhere to the protocol or complete the study.