1. Department of Diagnostic Radiology, Institute of Gastroenterology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
3. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.