1. Department of Radiology, Toranomon Hospital, Tokyo, Japan
2. Department of Radiological Technology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
3. Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, National Institute for Quantum Science and Technology, Chiba, Chiba, Japan
4. Department of Endovascular Neurosurgery, Toranomon Hospital, Tokyo, Japan
5. Division for Stroke Prevention and Treatment, Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan