1. Division of Neurology, Department of Internal Medicine, Saga University Faculty of Medicine, Saga, Japan
2. Department of Neurosurgery, Saga University Faculty of Medicine, Saga, Japan
3. Department of Radiology, Saga University Faculty of Medicine, Saga, Japan
4. Education and Research Center for Community Medicine, Saga University Faculty of Medicine, Saga, Japan
5. Department of Radiology, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
6. Department of Radiology, Yuai-Kai Oda Hospital, Kashima, Japan