[1] Yonsei Univ, Coll Med, Severance Hosp, Dept Radiol, Seoul, South Korea
[2] Catholic Univ Korea, Yeouido St Marys Hosp, Coll Med, Div Gastroenterol,Dept Internal Med, Seoul, South Korea
[3] Chonbuk Natl Univ, Med Sch & Hosp, Dept Radiol, 20 Geonji Ro, Jeonju 54907, Chonbuk, South Korea
[4] Chonbuk Natl Univ, Res Inst Clin Med, 20 Geonji Ro, Jeonju 54907, Chonbuk, South Korea
[5] Chonbuk Natl Univ Hosp, Biomed Res Inst, 20 Geonji Ro, Jeonju 54907, Chonbuk, South Korea