title: Evaluation of airway obstruction using virtual endoscopy.
abstract: OBJECTIVE
  This study examines the use of virtual endoscopy (VE) in the evaluation of patients with upper airway obstruction. The utility of VE compared with actual endoscopy was investigated with respect to accuracy of diagnosis and reproduction of endoscopic images.
  
  
  METHODS
  A random cohort of 30 patients with various causes of airway obstruction was examined.
  
  
  METHODS
  The computed tomography (CT) data were reconstructed using a proprietary VE software program, FreeFlight, blind to the actual endoscopic findings. The cause of obstruction was identified and compared with actual endoscopic findings. This included 21 patients with airway stenoses, 8 patients with laryngotracheomalacia, 3 tracheal tumors, 2 glottic webs, 5 patients with innominate artery compression, 2 tracheal granulomas, and 7 patients with impaired true vocal cord mobility.
  
  
  RESULTS
  Virtual endoscopic evaluation was accurate in assessing stenosis width and length of fixed airway lesions. Correlation of stenosis shape and contour between actual endoscopy and VE was excellent. The stenosis-to-lumen ratios were compared between VE and actual endoscopy and were found to be within 10% (SD = 8). However, virtual endoscopic evaluation could not illustrate one of the glottic webs, half of the cases of tracheomalacia, or any of the cases of impaired true vocal cord mobility.
  
  
  CONCLUSIONS
  Virtual endoscopy was not as sensitive as actual endoscopy in detecting the cause of airway obstruction that was based on dynamic movement. However, VE was excellent for the measurement and definition of fixed airway lesions.
authors.affiliation: Department of Otolaryngology, Wake Forest University Medical Center, Winston-Salem, North Carolina 27157, USA. alanjcburke@hotmail.com
authors.forename: A J
authors.initials: AJ
authors.lastname: Burke
authors.forename: D J
authors.initials: DJ
authors.lastname: Vining
authors.forename: W F
authors.initials: WF
authors.lastname: McGuirt
authors.forename: G
authors.initials: G
authors.lastname: Postma
authors.forename: J D
authors.initials: JD
authors.lastname: Browne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology; D001995:Bronchography; D001999:Bronchoscopy / Q000379:methods* / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008875:Middle Aged; D015203:Reproducibility of Results; D012135:Respiratory Sounds / Q000175:diagnosis / Q000209:etiology; D014057:Tomography, X-Ray Computed; D014584:User-Computer Interface