[1] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Radiol,Res Inst Radiol, 388-1 Pungnap2 Dong, Seoul 138736, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Obstet & Gynecol, Seoul 138736, South Korea
[3] Hanyang Univ, Guri Hosp, Dept Radiol, Seoul 133791, South Korea