1. Department of Radiology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
2. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
4. Department of Radiology, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
5. Department of Radiology, Korea University Guro Hospital, College of Medicine Korea University, Seoul, Korea.