1. Yonsei University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
3. Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
4. Yonsei Liver Center, Severance Hospital, Seoul, Korea.
5. Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.