title: Tracheobronchial anomalies and stenoses: detection with low-dose multidetector CT with virtual tracheobronchoscopy--comparison with flexible tracheobronchoscopy.
abstract: OBJECTIVE
  To prospectively assess the sensitivity and specificity of low-dose multidetector computed tomography (CT) with virtual tracheobronchoscopy (VT) for evaluation of suspected airway stenoses and/or abnormalities by using flexible tracheobronchoscopy (FT) as the reference standard.
  
  
  METHODS
  The study was approved by the local ethics committee; parental consent was obtained. Forty-five patients with clinically and/or radiographically suspected tracheobronchial stenosis and/or anomaly underwent FT and contrast material-enhanced single-phase multidetector CT with VT. CT was performed with an age- and weight-adjusted low-dose protocol: 120 or 80 kV; 120 or 60 mA; collimation, 1.5 or 0.75 mm; gantry rotation, 0.5 second. Mean effective dose was calculated for all examinations. Postprocessing was performed with surface rendering of VT images and multiplanar reformations. CT images were analyzed in consensus by two radiologists who were blinded to FT results. Statistical analysis was performed with 2 x 2 contingency tables; 95% confidence intervals (CIs) were calculated with the Blyth-Still-Casella procedure.
  
  
  RESULTS
  Mean patient age was 4.4 years (range, 2 months to 16 years; 53% male patients). Tracheobronchial narrowing and/or abnormality were depicted at FT in 38 of 45 patients. In 33 of 38 patients, multidetector CT with VT depicted a tracheobronchial narrowing and/or anomaly. In 10 of 38 patients, tracheobronchial stenosis was induced by vascular anomalies. Five patients with normal findings at multidetector CT with VT had tracheobronchomalacia with inspiratory airway stenosis at FT. Sensitivity and specificity of CT with VT were 86.8% (95% CI: 73.3%, 94.7%) and 85.7% (95% CI: 44.6%, 99.3%), respectively. Positive and negative predictive values were 97.1% (95% CI: 84.9%, 99.9%) and 54.5% (95% CI: 25.0%, 80.0%), respectively. Overall accuracy was 86.7% (95% CI: 74.3%, 94.0%). Mean effective dose was 1.1 mSv (range, 0.5-1.8 mSv).
  
  
  CONCLUSIONS
  Multidetector CT with VT with a low-dose protocol had high sensitivity and specificity for depiction of tracheobronchial narrowings and/or anomalies. However, tracheal narrowing due to tracheobronchomalacia was difficult to diagnose at single-phase multidetector CT with VT.
authors.affiliation: Institute of Diagnostic Radiology, Interventional Radiology and Nuclear Medicine, BG Clinics Bergmannsheil, Ruhr-University of Bochum, Buerkle-de-la-Camp Platz 1, D-44789 Bochum, Germany. christopher.heyer@rub.de
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Heyer
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Nuesslein
authors.forename: David
authors.initials: D
authors.lastname: Jung
authors.forename: Soeren A
authors.initials: SA
authors.lastname: Peters
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Lemburg
authors.forename: Christian H L
authors.initials: CH
authors.lastname: Rieger
authors.forename: Volkmar
authors.initials: V
authors.lastname: Nicolas
mesh_terms: D000293:Adolescent; D001980:Bronchi / Q000002:abnormalities*; D001982:Bronchial Diseases / Q000000981:diagnostic imaging; D001995:Bronchography / Q000379:methods*; D001999:Bronchoscopy / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D003287:Contrast Media; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014132:Trachea / Q000002:abnormalities* / Q000000981:diagnostic imaging; D014133:Tracheal Diseases / Q000000981:diagnostic imaging; D014135:Tracheal Stenosis / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media