title: Magnetic resonance imaging in patients with granulomatosis with polyangiitis (Wegener's) and subglottic stenosis.
abstract: OBJECTIVE
  To evaluate the ability of MRI to detect subglottic stenosis and to differentiate between active and inactive subglottic inflammation in patients with granulomatosis with polyangiitis (GPA).
  
  
  METHODS
  MRI studies of the larynx of 18 GPA patients with suspected SGS were included. The MRI protocol included T1- and T2-weighted and STIR-sequences, dynamic contrast enhancement (DCE) and diffusion weighted imaging (DWI). Two independent observers reviewed the MR images. SGS were identified and quantified, inflammatory activity was assessed using edema imaging, DCE and DWI. Final MRI diagnoses were compared to the clinical, laryngoscopic and histopathologic results.
  
  
  RESULTS
  MRI confirmed SGS in all GPA patients with significant narrowing of the airway lumen and thickening of subglottic wall. Assessing the subglottic inflammatory activity, MRI showed a sensitivity of 87.5 % and a specificity of 60.0 %. Interrater agreement was κ = 0.769. Of the different MR technical approaches tested, edema imaging was most sensitive and specific. DWI led to significant differences in the apparent diffusion coefficient between active and inactive subglottic inflammation. No significant differences were found with DCE imaging.
  
  
  CONCLUSIONS
  MR imaging has shown the ability to detect and grade SGS in patients with GPA. It non-invasively assesses the status of inflammatory activity utilizing edema sensitive sequences and DWI.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany. t.klink@uke.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Klink
authors.forename: Julia
authors.initials: J
authors.lastname: Holle
authors.forename: Martin
authors.initials: M
authors.lastname: Laudien
authors.forename: Frank Oliver
authors.initials: FO
authors.lastname: Henes
authors.forename: Frank
authors.initials: F
authors.lastname: Moosig
authors.forename: Corinna
authors.initials: C
authors.lastname: Platzek
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Wolfgang-Ludwig
authors.initials: WL
authors.lastname: Gross
authors.forename: Thorsten Alexander
authors.initials: TA
authors.lastname: Bley
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000150:complications* / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007829:Laryngostenosis / Q000175:diagnosis* / Q000209:etiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity