1. Neurovascular Research Lab; Department of Radiology, Massachusetts General Hospital, Harvard Medical School; Charlestown MA USA
2. Department of Neurology; Neurological Institute, Taipei Veterans General Hospital; Taipei Taiwan
3. Faculty of Medicine; National Yang-Ming University School of Medicine; Taipei Taiwan
4. Institute of Clinical Medicine; National Yang-Ming University School of Medicine; Taipei Taiwan
5. Stroke Service and Neuroscience Intensive Care Unit; Department of Neurology, Massachusetts General Hospital, Harvard Medical School; Charlestown MA USA