title: Comparing three-dimensional volume-rendered CT images with fibreoptic tracheobronchoscopy in the evaluation of airway compression caused by tuberculous lymphadenopathy in children.
abstract: BACKGROUND
  Lymphobronchial tuberculosis (TB) causes airway compression in 38% of patients. The airway obstruction is conventionally assessed with fibreoptic tracheobronchoscopy (FTB). Multidetector-row spiral computed tomography (MDCT) with three-dimensional volume rendering (3-D VR) has significantly improved the imaging of the airways. No previous studies have assessed the accuracy of 3-D VR in determining the degree of airway compression in children due to TB lymphadenopathy.
  
  
  OBJECTIVE
  To compare 3-D VR CT to FTB for the assessment of airway compression due to TB lymphadenopathy in children.
  
  
  METHODS
  Included in the study were 26 children presenting with symptoms of airway compression caused by pulmonary TB. MDCT of the chest and FTB were performed in all patients. Retrospective 3-D VR reconstruction of the major airways was performed from the original CT raw data and used to evaluate the tracheobronchial tree for site and degree of airway compression and then compared to the FTB findings. FTB was used as the reference standard
  
  
  RESULTS
  By FTB 87 sites of airway compression were identified. Using the 3-D VR technique, 138 sites of airway compression were identified, of which 78 (90%) matched with the sites identified by FTB. The sensitivity and specificity of 3-D VR when compared with that of FTB was 92% and 85%, respectively. In four patients (15%), severe narrowing of the bronchus intermedius made FTB evaluation of the right middle and right lower lobe bronchi impossible. VR demonstrated significant distal obstruction in three of these four patients
  
  
  CONCLUSIONS
  3-D VR demonstrates a very good correlation with FTB in determining airway compression caused by TB lymphadenopathy in children. In combination with FTB, 3-D VR adds confidence to the bronchoscopy findings and complements FTB by adding additional information on the status of the airway distal to severe obstructions unreachable by FTB.
authors.affiliation: Department of Radiology, University of Stellenbosch, P.O. Box 19063, Tygerberg, 7505, South Africa. drjjdup@hotmail.com
authors.forename: Jaco
authors.initials: J
authors.lastname: du Plessis
authors.forename: Pierre
authors.initials: P
authors.lastname: Goussard
authors.forename: Savvas
authors.initials: S
authors.lastname: Andronikou
authors.forename: Robert
authors.initials: R
authors.lastname: Gie
authors.forename: Reena
authors.initials: R
authors.lastname: George
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology*; D000465:Algorithms; D001999:Bronchoscopy / Q000379:methods*; D005336:Fiber Optic Technology; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007828:Laryngoscopy / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014388:Tuberculosis, Lymph Node / Q000150:complications* / Q000175:diagnosis*