1. Department of Veterinary Radiology, Yamaguchi University, 1677-1 Yoshida, Yamaguchi City, Yamaguchi 753-8515, Japan
2. Department of Veterinary Small Animal Clinical Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi City, Yamaguchi 753-8515, Japan
3. Department of Veterinary Surgery, Joint Faculty of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi City, Yamaguchi 753-8515, Japan