1. Department of Radiology, Severance Hospital, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Radiology, Konyang University Hospital, Konyang University College of Medicine, Seoul, Korea.
3. Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
4. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Biostatistics Collaboration Unit, Medical Research Center, Yonsei University College of Medicine, Seoul, Korea.