1. Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels – Akita, 6–10 Senshu-Kubota Machi, Akita, Akita, Japan
2. Course of Radiological Technology, Health Sciences, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Sendai, Miyagi, Japan
3. Department of Cardiology, Division of Internal Medicine, Research Institute for Brain and Blood Vessels – Akita, 6–10 Senshu-Kubota Machi, Akita, Akita, Japan