1. Department of Radiology, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Hospital, Busan 49241, Korea.
2. Department of Diagnostic Radiology, National Cancer Center, Goyang 10408, Korea.
3. Department of Radiology, Seoul National University College of Medicine, Seoul 03080, Korea.
4. Department of Radiology, Gachon University Gil Medical Center, Incheon 21565, Korea.
5. Department of Radiology, Chungbuk National University Hospital, Cheongju 28644, Korea.
6. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
7. Cancer Early Detection Branch, National Cancer Control Institute, National Cancer Center, Goyang 10408, Korea.