[1] Univ Ulsan, Dept Pediat, Asan Med Ctr, Coll Med, Seoul, South Korea
[2] Korea Adv Inst Sci & Technol KAIST, Grad Sch Med Sci & Engn, Daejeon, South Korea
[3] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Radiol, Seoul, South Korea
[4] Univ Ulsan, Coll Med, Asan Med Ctr, Res Inst Radiol, Seoul, South Korea
[5] Univ Ulsan, Dept Pediat Surg, Asan Med Ctr, Coll Med, Seoul, South Korea