1. Department of Radiological Sciences, Graduate School of Medicine, Nagoya University, 1-1-20 Daikominami, Higashi-ku, Nagoya 461-8673, Japan
2. Division of Radiology, Aichi Medical University Hospital, Nagakute, Aichi 480-1195, Japan
3. Techno-Rad, Inc., 50-8, Higashi Arami, Tai, Miyama-cho, Kuze-gun, Kyoto 613-0036, Japan
4. Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan