title: Accuracy of virtual bronchoscopy to detect endobronchial lesions.
abstract: BACKGROUND
  Virtual bronchoscopy (VB) could obviate flexible bronchoscopy (FB) if no endobronchial lesion is detected in patients presenting with a suspicion of malignancy. Our objectives were to evaluate the accuracy (in terms of sensitivity and specificity) of VB in detecting endobronchial lesions, and to determine the anatomical limit of detection of endobronchial lesions by VB.
  
  
  METHODS
  This study involved, in a blind comparison of VB and FB, consecutive patients presenting with symptoms or plain chest radiography abnormalities raising the suspicion of pulmonary neoplasm. After the standard chest computed tomography (CT), additional helical CT data were acquired from the aortic arch to the origin of the segmental bronchi of the inferior lobes in one 20-second breath hold using an helicoidal CT scan (3.0-mm collimation with a pitch of 1.5 and 1.5-mm reconstruction intervals).
  
  
  RESULTS
  One hundred ninety patients were enrolled; 136 patients (including 63 with an endobronchial lesion at FB) contributed to the primary analysis. The sensitivity and specificity of VB to detect endobronchial lesions were 68% (95% confidence interval [CI]: 55% to 79%) and 90% (95% CI: 81% to 96%), respectively. Overall, the agreement between VB and FB regarding the location on endobronchial lesions was substantial (weighted kappa: 0.66). However, VB detected only 26 of the 34 lobar lesions (sensitivity: 76%; CI: 59% to 89%) and 11 of the 23 segmental lesions (sensitivity: 48%; CI: 27% to 69%).
  
  
  CONCLUSIONS
  Beyond the mainstem bronchi, VB is not accurate enough to detect endobronchial lesions and to obviate FB in patients presenting with a suspicion of malignancy.
authors.affiliation: Centre de Recherche and Department of Radiology, Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie de l'Université Laval, Sainte-Foy, Quebec, Canada. yves.lacasse@med.ulaval.ca
authors.forename: Yves
authors.initials: Y
authors.lastname: Lacasse
authors.forename: Simon
authors.initials: S
authors.lastname: Martel
authors.forename: Amélie
authors.initials: A
authors.lastname: Hébert
authors.forename: Guy
authors.initials: G
authors.lastname: Carrier
authors.forename: Bruno
authors.initials: B
authors.lastname: Raby
mesh_terms: D001984:Bronchial Neoplasms / Q000175:diagnosis*; D001995:Bronchography; D001999:Bronchoscopy / Q000379:methods*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis*; D018288:Carcinoma, Small Cell / Q000175:diagnosis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed