1. Pusan National University School of Medicine, Yangsan 50612, Korea.
2. Department of Radiology, Pusan National University Yangsan Hospital, Biomedical Research Institute, Yangsan 50612, Korea.
3. Department of Radiology, Pusan National University Hospital, Biomedical Research Institute, Busan 49241, Korea.
4. Department of Radiology, Inje University Haeundae Paik Hospital, Busan 48108, Korea.