1. Department of Neurology and Psychiatry, Emergency and Critical Care Medical Center, Beijing Shijitan Hospital Capital Medical University Beijing China
2. Department of Neurology Dalian Municipal Central Hospital Dalian Liaoning China
3. Department of Neurointervention Dalian Municipal Central Hospital Dalian Liaoning China
4. The Russell H. Morgan Department of Radiology and Radiological Sciences The Johns Hopkins University School of Medicine Baltimore MD USA