1. Department of Radiology, GangNeung Asan Hospital, University of Ulsan College of Medicine, GangNeung 210-711, Korea.
2. Department of Preventive Medicine, University of Kwandong College of Medicine, GangNeung 210-701, Korea.
3. Department of Orthopedic Surgery, GangNeung Asan Hospital, University of Ulsan College of Medicine, GangNeung 210-711, Korea.
4. Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.