1. Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-0052, Japan
2. Department of Veterinary Clinical Medicine, Faculty of Agriculture, Iwate University, 3-18-8 Ueda-cho, Morioka-shi, Iwate 020-8550, Japan
3. Department of Veterinary Diagnostic imaging, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-0052, Japan