1. Department of Otolaryngology; Faculty of Medicine; Graduate School of Medicine; University of Tokyo; Tokyo Japan
2. Department of Artificial Organs and Otolaryngology; National Institute of Sensory Organs; Tokyo Japan
3. Department of Otolaryngology; Social Insurance Central General Hospital; Tokyo Japan
4. Department of Radiology; Faculty of Medicine; Graduate School of Medicine; University of Tokyo; Tokyo Japan
5. Department of Radiology; Toho University Omori Medical Center; Tokyo Japan