[1] Int Univ Hlth, Welf Mita Hosp, Dept Radiol, 1-4-3 Mita, Minato, Tokyo 1088329, Japan
[2] Int Univ Hlth, Welf Narita Hosp, Dept Radiol, 852 Hatakeda Narita, Chiba 2860124, Japan
[3] Univ Tokyo, Inst Med Sci, Dept Radiol, 4-6-1 Shirokanedai, Minato, Tokyo 1088639, Japan
[4] Univ Tokyo, Grad Sch Med, Dept Radiol, 7-3-1 Hongo, Bunkyo, Tokyo 1130033, Japan
[5] Int Univ Hlth & Welf, 2600-1 kitakanamaru, Otawara, Tochigi 3248501, Japan