[1] Korea University College of Medicine,Department of Internal Medicine
[2] Korea University College of Medicine,Department of Internal Medicine, Division of Gastroenterology and Hepatology, Guro Hospital
[3] Chonnam National University Medical School,Department of Gastroenterology and Hepatology, Chonnam National University Hwasun Hospital
[4] Dongnam Institute of Radiological and Medical Sciences,Department of Internal Medicine and Gastrointestinal Cancer Center
[5] Yonsei University College of Medicine,Department of Internal Medicine, Gangnam Severance Hospital
[6] Soonchunhyang University College of Medicine Seoul Hospital,Department of Internal Medicine