[1] Univ Tokyo, Grad Sch Med, Dept Radiol, 7-3-1 Hongo,Bunkyo Ku, Tokyo 1138655, Japan
[2] Int Univ Hlth & Welf, Dept Radiol, Narita Hosp, 852 Hatakeda, Narita, Chiba 2860124, Japan
[3] Int Univ Hlth, Welf Mita Hosp, Dept Radiol, 1-4-3 Mita,Minato Ku, Tokyo 1088329, Japan
[4] Univ Tokyo, Inst Med Sci, Dept Radiol, 4-6-1 Shirokanedai,Minato Ku, Tokyo 1088639, Japan
[5] Int Univ Hlth & Welf, 2600-1 Ktiakanemaru, Ohtawara, Tochigi 3248501, Japan