title: Measuring the airway in 3 dimensions: a reliability and accuracy study.
abstract: BACKGROUND
  The aim of the study was to compare the reliability and accuracy of 3 commercially available digital imaging and communications in medicine (DICOM) viewers for measuring upper airway volumes.
  
  
  METHODS
  Thirty cone-beam computed tomography scans were randomly selected, and the upper airway volumes were calculated for both oropharynx and nasal passage. Dolphin3D (version 11, Dolphin Imaging & Management Solutions, Chatsworth, Calif), InVivoDental (version 4.0.70, Anatomage, San Jose, Calif), and OnDemand3D (version 1.0.1.8407, CyberMed, Seoul, Korea) were compared with a previously tested manual segmentation program called OrthoSegment (OS) (developed at the Department of Orthodontics at Case Western Reserve University, Cleveland, Ohio). The measurements were repeated after 2 weeks, and the ICC was used for the reliability tests. All commercially available programs were compared with the OS program by using regression analysis. The Pearson correlation was used to evaluate the correlation between the OS and the automatic segmentation programs.
  
  
  RESULTS
  The reliability was high for all programs. The highest correlation found was between the OS and Dolphin3D for the oropharynx, and between the OS and InVivoDental for nasal passage volume. A high correlation was found for all programs, but the results also showed statistically significant differences compared with the OS program. The programs also had inconsistencies among themselves.
  
  
  CONCLUSIONS
  The 3 commercially available DICOM viewers are highly reliable in their airway volume calculations and showed high correlation of results but poor accuracy, suggesting systematic errors.
authors.affiliation: Department of Orthodontics, School of Dental Medicine, Hacettepe University, Ankara, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: El
authors.forename: Juan Martin
authors.initials: JM
authors.lastname: Palomo
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009296:Nasal Cavity / Q000000981:diagnostic imaging*; D009960:Oropharynx / Q000000981:diagnostic imaging*; D011873:Radiology Information Systems; D012986:Software Validation