1. Department of Veterinary Radiology; Nihon University; 1866, Kameino Fujisawa Kanagawa 252-8510 Japan
2. Department of Pathology; Nihon University; 1866, Kameino Fujisawa Kanagawa 252-8510 Japan
3. Department of Internal Medicine; College of Bioresource Sciences; Nihon University; 1866, Kameino Fujisawa Kanagawa 252-8510 Japan
4. Department of Neurosurgery; School of Medicine; Nihon University; 1-30, Kamimachi, Otaniguchi Itabashi-Ku Tokyo 173-8605 Japan