1. Department of Urology, Kurume University School of Medicine , Kurume , Japan
2. Dental and Oral Medical Center, Kurume University School of Medicine , Kurume , Japan
3. Advanced Imaging Research Center, Kurume University School of Medicine , Kurume , Japan
4. Division of Microscopic and Development Anatomy, Department of Anatomy, Kurume University School of Medicine , 67 Asahi-machi, Kurume 830-0011 , Japan