1. Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
3. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.