[1] Catholic Kwandong Univ, Int St Marys Hosp, Dept Internal Med, Coll Med, Incheon 22711, South Korea
[2] Yonsei Univ, Dept Med, Grad Sch, 50-1 Yonsei Ro, Seoul 03722, South Korea
[3] Yonsei Univ, Dept Internal Med, Div Gastroenterol, Coll Med, 50-1 Yonsei Ro, Seoul 03722, South Korea
[4] Yonsei Univ, Dept Radiol, Coll Med, 50-1 Yonsei Ro, Seoul 03722, South Korea