1. Department of Radiology, Seoul National University Hospital, Seoul, Korea.
2. Department of Radiology, Seoul National College of Medicine, Seoul, Korea.
3. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
4. Medical Research Collaborating Center, Seoul National University Hospital, Seoul, Korea.
5. Department of Radiology, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea.