1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
2. Department of Radiology, Kyungpook National University Medical Center, School of Medicine, Kyungpook National University, Daegu, Korea.
3. Department of Radiology, Ewha Womans University Seoul Hospital, Seoul, Korea.
4. Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
5. Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
6. Department of Radiology, Kyung Hee University Hospital, Seoul, Korea.
7. Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.