1. Department of Gastroenterology and Hepatology, Kinki University Faculty of Medicine, Osaka-sayama, Japan
2. Section of Abdominal Ultrasound, Kinki University Faculty of Medicine, Osaka-sayama, Japan
3. Department of Pathology, Kinki University Faculty of Medicine, Osaka-sayama, Japan
4. Department of Radiology, Kinki University Faculty of Medicine, Osaka-sayama, Japan
5. Division of Biostatistics, Clinical Research Center, Kinki University Faculty of Medicine, Osaka-sayama, Japan
6. Department of Surgery, Kinki University Faculty of Medicine, Osaka-sayama, Japan