title: Quantification of pulmonary inflammation after segmental allergen challenge using turbo-inversion recovery-magnitude magnetic resonance imaging.
abstract: BACKGROUND
  There is a need to develop novel noninvasive imaging biomarkers that help to evaluate antiinflammatory asthma treatments.
  
  
  OBJECTIVE
  To investigate whether the extent of the segmental lung edema measured noninvasively using turbo-inversion recovery-magnitude magnetic resonance imaging (TIRM MRI) corresponds to the severity of the regional allergic reaction determined by the percentage of eosinophils in bronchoalveolar lavage fluid (BAL) 24 hours after segmental allergen challenge in patients with asthma compared with normal control subjects.
  
  
  METHODS
  Eleven volunteers with allergic asthma and five healthy volunteers underwent segmental challenges with different allergen doses by two bronchoscopies 24 hours apart. They had lung MRI at baseline and 6 and 24 hours after segmental challenge. MRI TIRM scores were correlated with the eosinophilic response at 24 hours.
  
  
  RESULTS
  In patients with asthma, there were significant differences of eosinophil percentages in BAL at 24 hours from segments given standard-dose, low-dose, or no allergen (saline) (P < 0.001). Correspondingly significant differences between the TIRM score in allergen standard-dose, low-dose, and saline-treated segments were observed at 24 hours post-challenge (P < 0.001). With increasing TIRM score at 24 hours the percent eosinophils per segment 24 hours post-challenge also increased accordingly (P < 0.001). There was interobserver agreement for TIRM score grading (kappa = 0.72 for 24-h time point).
  
  
  CONCLUSIONS
  The MRI-based noninvasive TIRM score is a promising biomarker for the noninvasive detection of the inflammatory response after segmental allergen challenge in patients with asthma and may serve to monitor the therapeutic effectiveness of novel antiinflammatory drugs in future human trials.
authors.affiliation: 1 Institute of Diagnostic and Interventional Radiology and.
authors.forename: Jens
authors.initials: J
authors.lastname: Vogel-Claussen
authors.forename: Julius
authors.initials: J
authors.lastname: Renne
authors.forename: Jan
authors.initials: J
authors.lastname: Hinrichs
authors.forename: Christian
authors.initials: C
authors.lastname: Schönfeld
authors.forename: Marcel
authors.initials: M
authors.lastname: Gutberlet
authors.forename: Frank
authors.initials: F
authors.lastname: Schaumann
authors.forename: Carla
authors.initials: C
authors.lastname: Winkler
authors.forename: Cornelia
authors.initials: C
authors.lastname: Faulenbach
authors.forename: Norbert
authors.initials: N
authors.lastname: Krug
authors.forename: Frank K
authors.initials: FK
authors.lastname: Wacker
authors.forename: Jens M
authors.initials: JM
authors.lastname: Hohlfeld
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D001985:Bronchial Provocation Tests / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D001999:Bronchoscopy; D016022:Case-Control Studies; D004804:Eosinophils; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012720:Severity of Illness Index