title: Do technical parameters affect the diagnostic accuracy of virtual bronchoscopy in patients with suspected airways stenosis?
abstract: OBJECTIVE
  Virtual bronchoscopy has gained popularity over the past decade as an alternative investigation to conventional bronchoscopy in the diagnosis, grading and monitoring of airway disease. The effect of technical parameters on diagnostic outcome from virtual bronchoscopy has not been determined. This meta-analysis aims to estimate accuracy of virtual compared to conventional bronchoscopy in patients with suspected airway stenosis, and evaluate the influence of technical parameters.
  
  
  METHODS
  A MEDLINE search was used to identify relevant published studies. The primary endpoint was the "correct diagnosis" of stenotic lesions on virtual compared to conventional bronchoscopy. Secondary endpoints included the effects of the technical parameters (pitch, collimation, reconstruction interval, rendering method, and scanner type), and date of publication on the diagnostic accuracy of virtual bronchoscopy.
  
  
  RESULTS
  Thirteen studies containing 454 patients were identified. Meta-analysis showed good overall diagnostic performance with 85% calculated pooled sensitivity (95% CI 77-91%), 87% specificity (95% CI 81-92%) and area under the curve (AUC) of 0.947. Subgroups included collimation of 3mm or more (AUC 0.948), pitch of 1 (AUC 0.955), surface rendering technique (AUC 0.935), and reconstruction interval of more than 1.25 mm (AUC 0.914). There was no significant difference in accuracy accounting for publication date, scanner type or any of the above variables. Weighted regression analysis confirmed none of these variables could significantly account for study heterogeneity.
  
  
  CONCLUSIONS
  Virtual bronchoscopy performs well in the investigation of patients with suspected airway stenosis. Overall sensitivity and specificity and diagnostic odds ratio for diagnosis of airway stenosis were high. The effects of pitch, collimation, reconstruction interval, rendering technique, scanner type, and publication date on diagnostic accuracy were not significant.
authors.affiliation: Imperial College of Science Technology and Medicine, Department of Surgical Oncology and Technology, St Mary's Hospital, Praed Street, London W2 1NY, UK.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Jones
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
authors.forename: Sujit
authors.initials: S
authors.lastname: Nair
authors.forename: Omer
authors.initials: O
authors.lastname: Aziz
authors.forename: Sanjay
authors.initials: S
authors.lastname: Purkayastha
authors.forename: Vlachos
authors.initials: V
authors.lastname: Konstantinos
authors.forename: Paraskevas
authors.initials: P
authors.lastname: Paraskeva
authors.forename: Roberto
authors.initials: R
authors.lastname: Casula
authors.forename: Brian
authors.initials: B
authors.lastname: Glenville
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis*; D019540:Area Under Curve; D001999:Bronchoscopy; D006801:Humans; D012680:Sensitivity and Specificity; D014584:User-Computer Interface