Center for Health Promotion,Department of Medicine,Samsung Medical Center,Sungkyunkwan University School of Medicine,50,Irwon-dong,Gangnam-gu,Seoul 135-710,South Korea;
Division of Gastroenterology,Department of Medicine,Samsung Medical Center,Sungkyunkwan University School of Medicine,50,Irwon-dong,Gangnam-gu,Seoul 135-710,South Korea;
Subepithelial tumor; Ultrasonography; Gastrointestinal diseases; Gastrointestinal endoscopy; Time factors;