1. Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-914, Korea.
2. Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
3. Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-701, Korea.
4. Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan 614-735, Korea.
5. Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 120-752, Korea.
6. Department of Radiology, Dong-A University Medical Center, Dong-A University College of Medicine, Busan 602-715, Korea.
7. Department of Radiology, Ansan Hospital, Korea University School of Medicine, Gyeonggi-do 425-707, Korea.
8. Human Medical Imaging & Intervention Center, Seoul 137-902, Korea.
9. Healthcare System Gangnam Center, Seoul National University Hospital, Seoul 135-984, Korea.
10. Department of Radiology, Hanyang University Hospital, Hanyang University College of Medicine, Seoul 133-792, Korea.
11. Department of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul 156-707, Korea.