1. Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan 614-735, Korea.
2. Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
3. Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 120-752, Korea.
4. Department of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan 612-896, Korea.
5. Department of Radiology, Thyroid Center, Daerim St. Mary's Hospital, Seoul 150-822, Korea.
6. Department of Radiology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul 140-743, Korea.