1. Department of Gastroenterology, Lianyungang Clinical College of Nanjing Medical University, Lianyungang, Jiangsu Province, P.R. China
2. Department of Gastroenterology, First Affliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, P.R. China
3. Department of Ultrasonography, First Affliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, P.R. China