1. Department of Radiology, Keimyung University College of Medicine, Daegu 700-712, Korea.
2. Mint Radiologic Clinic, Seongnam 463-950, Korea.
3. Department of Radiology, Inha University College of Medicine, Incheon 400-711, Korea.
4. Department of Radiology, Pusan National University College of Medicine, Busan 602-739, Korea.
5. Department of Radiology, Seoul National University College of Medicine, Seoul 110-744, Korea.
6. Department of Radiology, Sungkyunkwan University College of Medicine, Seoul 135-710, Korea.
7. Department of Radiology, Eulji University College of Medicine, Seoul 139-872, Korea.
8. Department of Radiology, Yonsei University College of Medicine, Seoul 120-752, Korea.