title: Anatomical reconstructions of pediatric airways from endoscopic images: a pilot study of the accuracy of quantitative endoscopy.
abstract: OBJECTIVE
  To evaluate the accuracy of three-dimensional (3D) airway reconstructions obtained using quantitative endoscopy (QE). We developed this novel technique to reconstruct precise 3D representations of airway geometries from endoscopic video streams. This method, based on machine vision methodologies, uses a post-processing step of the standard videos obtained during routine laryngoscopy and bronchoscopy. We hypothesize that this method is precise and will generate assessment of airway size and shape similar to those obtained using computed tomography (CT).
  
  
  METHODS
  This study was approved by the institutional review board (IRB). We analyzed video sequences from pediatric patients receiving rigid bronchoscopy.
  
  
  METHODS
  We generated 3D scaled airway models of the subglottis, trachea, and carina using QE. These models were compared to 3D airway models generated from CT. We used the CT data as the gold standard measure of airway size, and used a mixed linear model to estimate the average error in cross-sectional area and effective diameter for QE.
  
  
  RESULTS
  The average error in cross sectional area (area sliced perpendicular to the long axis of the airway) was 7.7 mm(2) (variance 33.447 mm(4)). The average error in effective diameter was 0.38775 mm (variance 2.45 mm(2)), approximately 9% error.
  
  
  CONCLUSIONS
  Our pilot study suggests that QE can be used to generate precise 3D reconstructions of airways. This technique is atraumatic, does not require ionizing radiation, and integrates easily into standard airway assessment protocols. We conjecture that this technology will be useful for staging airway disease and assessing surgical outcomes.
authors.affiliation: Department of Computer Science, The Johns Hopkins University, Baltimore, Maryland, U.S.A.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Meisner
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Hager
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Ishman
authors.forename: David
authors.initials: D
authors.lastname: Brown
authors.forename: David E
authors.initials: DE
authors.lastname: Tunkel
authors.forename: Masaru
authors.initials: M
authors.lastname: Ishii
mesh_terms: D001999:Bronchoscopy; D002648:Child; D003198:Computer Simulation; D061827:Dimensional Measurement Accuracy; D006801:Humans; D021621:Imaging, Three-Dimensional; D007828:Laryngoscopy; D010865:Pilot Projects; D012137:Respiratory System / Q000033:anatomy & histology*; D014741:Video Recording
keywords: Subglottic stenosis; airway reconstruction; computed tomography; endoscopy; pediatrics; quantitative endoscopy