1. Department of Radiological Technology, Toranomon Hospital, Tokyo, Japan
2. Stroke Center, Kyorin University Hospital, Tokyo, Japan
3. Cranial Nerve Surgery, National Hospital Organization Mito Medical Center, Higashiibaraki, Ibaraki, Japan
4. Division for Stroke, Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan