1. Department of Otolaryngology-Head and Neck Surgery; University of Pittsburgh Medical Center; Pittsburgh Pennsylvania U.S.A.
2. Departments of Radiology and Otolaryngology; University of Pittsburgh Medical Center; Pittsburgh Pennsylvania U.S.A.
3. Division of Pediatric General and Thoracic Surgery; Children's Hospital of Pittsburgh; University of Pittsburgh Medical Center; Pittsburgh Pennsylvania U.S.A.
4. Department of Pediatric Otolaryngology; Children's Hospital of Pittsburgh; University of Pittsburgh Medical Center; Pittsburgh Pennsylvania U.S.A.