1. Department of Radiology, St. Vincent's Hospital, The Catholic University of Korea, Kyunggi-do 442-723, Korea.
2. Department of Radiology, Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon 403-720, Korea.
3. Department of Pathology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-107, Korea.