1 Department of Otolaryngology, Japanese Red Cross Society Himeji Hospital, Himeji.
2 Department of Radiological Technology, Okayama University Graduate School of Health Sciences, Okayama.
3 Departments of Pathology, Japanese Red Cross Society Himeji Hospital, Himeji.
4 Department of Otolaryngology Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.