1 Department of Radiology, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Uijeongbu 480717, South Korea.
2 Department of General Surgery, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Uijeongbu 480717, South Korea.
3 Department of Gastroenterology, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, 271, Cheonbo-ro, Uijeongbu 480717, South Korea. Electronic address: yscho@catholic.ac.kr.