1. Department of Radiology, Keimyung University, School of Medicine & Dongsan Medical Center, Daegu, Korea.
2. Department of Radiology, Ulsan University Hospital, University of Ulsan College of Medicine, Korea.
3. Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
5. Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University College of Medicine, Seoul, Korea.