1. Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.
2. Department of Radiology, National Cancer Center, Goyang, Korea.
3. Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
4. Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
5. Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
6. Department of Radiology, Inje University Sanggye Paik Hospital, Seoul, Korea.
7. Department of Radiology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
8. Department of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Korea.
9. Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
10. Department of Statistics, Inha University, Incheon, Korea.
11. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.