1. Department of Radiology; Chiba University Hospital; 1-8-1 Inohana, Chou-ku Chiba Chiba 260-8677 Japan
2. Department of Internal Medicine; University of California; San Diego, 9500 Gilman Dr. La Jolla CA 92093 USA
3. Department of Radiology, Institute of Clinical Medicine; University of Tsukuba; 1-1-1 Ten-noudai Tsukuba Ibaraki 305-8575 Japan
4. Department of Surgery, Institute of Clinical Medicine; University of Tsukuba; 1-1-1 Ten-noudai Tsukuba Ibaraki 305-8575 Japan
5. Department of Pathology; Teikyo University School of Medicine; 2-11-1 Kaga, Itabashi-ku Tokyo 173-8605 Japan