1. Department of Radiology, National Cancer Center, Goyang 10408, Korea.
2. Department of Radiology, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 06591, Korea.
3. Department of Surgery, College of Medicine, Bucheon St. Mary's Hospital, The Catholic University of Korea, Bucheon 14647, Korea.
4. Department of Pathology, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 06591, Korea.