1. Department of Diagnostic Radiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
2. Department of Urology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
3. Department of Diagnostic Pathology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
4. Department of Urology, Nerima General Hospital, Nerima-ku, Tokyo, Japan