1. Department of Radiology, Seoul National University Hospital, Seoul, Korea.
2. Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
3. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
4. Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
5. Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.