[1] Seoul Natl Univ Hosp, Dept Radiol, Seoul 110744, South Korea
[2] Seoul Natl Univ Hosp, Clin Res Inst, Seoul 110744, South Korea
[3] Seoul Natl Univ, Med Res Ctr, Inst Radiat Med, Seoul, South Korea
[4] Seoul Natl Univ, Boramae Hosp, Dept Radiol, Seoul, South Korea
[5] Natl Canc Ctr, Dept Radiol, Gyeonggi Do, South Korea