1. Department of Diagnostic Radiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
2. Department of Pathology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
3. Department of Surgery, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
4. Department of Surgery, Hiratsuka City Hospital, Kanagawa, Japan
5. Department of Diagnostic Radiology, Hiratsuka City Hospital, Kanagawa, Japan