1. Department of Urology, The University of Tokyo Hospital, Hongou 7-3-1, Bunkyo-ku, Tokyo 1138655, Japan
2. Department of Urology, Fraternity Memorial Hospital, Yokoami 2-1-11, Sumida-ku, Tokyo 1308587, Japan
3. Department of Radiology, Fraternity Memorial Hospital, Yokoami 2-1-11, Sumida-ku, Tokyo 1308587, Japan