1. Department of Diagnostic Radiology, Gachon University Gil Medical Center, Incheon 405-760, Korea.
2. Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul 120-752, Korea.
3. Department of Diagnostic Radiology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul 110-746, Korea.
4. Department of Pathology, Yonsei University College of Medicine, Seoul 120-752, Korea.
5. Department of General Surgery, Yonsei University College of Medicine, Seoul 120-752, Korea.