1. School of Medicine, Chiba University, Chiba, Japan
2. Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
3. Department of Radiology, Chiba University Hospital, Chiba, Japan
4. Department of Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
5. Department of Health Sciences, Unit of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
6. Department of Neurological Sciences, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
7. Department of Medical Education, Graduate School of Medicine, Chiba University, Chiba, Japan