[1] Okayama Univ, Dept Radiol, Sch Med, Kita Ku, Okayama 7008558, Japan
[2] Kawasaki Hosp, Kawasaki Med Sch, Dept Diagnost Radiol 2, Kita Ku, Okayama 7008505, Japan
[3] Okayama Saiseikai Gen Hosp, Dept Radiol, Kita Ku, Okayama 7008511, Japan
[4] Fukuyama Med Ctr, Dept Radiol, Fukuyama, Hiroshima 7208520, Japan
[5] Okayama Med Ctr, Dept Radiol, Kita Ku, Okayama 7011192, Japan
[6] Tsuyama Chuo Hosp, Dept Radiol, Tsuyama, Okayama 7080841, Japan
[7] Chugoku Chuo Hosp, Dept Radiol, Fukuyama, Hiroshima 7200001, Japan
[8] Himeji Red Cross Hosp, Dept Radiol, Himeji, Hyogo 6708540, Japan
[9] Fukuyama City Hosp, Dept Diagnost & Intervent Radiol, Fukuyama, Hiroshima 7218511, Japan
[10] Okayama Red Cross Hosp, Dept Radiol, Kita Ku, Okayama 7008607, Japan
[11] Iwakuni Med Ctr, Dept Radiol, Iwakuni, Yamaguchi 7408510, Japan
[12] Mitoyo Gen Hosp, Dept Radiol, Kanonji, Kagawa 7691695, Japan
[13] Okayama Univ, Dept Epidemiol, Sch Med, Kita Ku, Okayama 7008558, Japan