title: PRAGMA-CF. A Quantitative Structural Lung Disease Computed Tomography Outcome in Young Children with Cystic Fibrosis.
abstract: BACKGROUND
  Chest computed tomography (CT) is the gold standard for demonstrating cystic fibrosis (CF) airway disease. However, there are no standardized outcome measures appropriate for children younger than 6 years.
  
  
  OBJECTIVE
  We developed the Perth-Rotterdam Annotated Grid Morphometric Analysis for CF (PRAGMA-CF), a quantitative measure of airway disease, and compared it with the commonly used CF-CT scoring method.
  
  
  METHODS
  CT scans from the Australian Respiratory Early Surveillance Team for CF (AREST CF) cohort in Western Australia were included. PRAGMA-CF was performed by annotating a grid overlaid on 10 axial slices for the presence of bronchiectasis, mucous plugging, or other airway abnormalities (inspiratory scans) and trapped air (expiratory scans). The separate proportions of total disease (%Dis), bronchiectasis (%Bx), and trapped air (%TA) were determined. Thirty scans were used for observer reliability, and 30 paired scans obtained at 1 and 3 years old were used for comparison with a validated standard and biologic plausibility.
  
  
  RESULTS
  Intraobserver, intraclass correlation coefficients (95% confidence interval) for %Dis, %Bx, and %TA were 0.93 (0.86-0.97), 0.93 (0.85-0.96), and 0.96 (0.91-0.98), respectively. The change in %Dis (P = 0.004) and %Bx (P = 0.001) with PRAGMA-CF was related to neutrophil elastase presence at age 3, whereas only the change in bronchiectasis score was related to neutrophil elastase (P < 0.001) with CF-CT. Sample-size calculations for various effect sizes are presented.
  
  
  CONCLUSIONS
  PRAGMA-CF is a sensitive and reproducible outcome measure for assessing the extent of lung disease in very young children with CF.
authors.affiliation: 1 School of Paediatrics and Child Health and.
authors.forename: Tim
authors.initials: T
authors.lastname: Rosenow
authors.forename: Merel C J
authors.initials: MC
authors.lastname: Oudraad
authors.forename: Conor P
authors.initials: CP
authors.lastname: Murray
authors.forename: Lidija
authors.initials: L
authors.lastname: Turkovic
authors.forename: Wieying
authors.initials: W
authors.lastname: Kuo
authors.forename: Marleen
authors.initials: M
authors.lastname: de Bruijne
authors.forename: Sarath C
authors.initials: SC
authors.lastname: Ranganathan
authors.forename: Harm A W M
authors.initials: HA
authors.lastname: Tiddens
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Stick
mesh_terms: D001987:Bronchiectasis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D002675:Child, Preschool; D002986:Clinical Trials as Topic / Q000379:methods; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007223:Infant; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014904:Western Australia
keywords: clinical trials as topic; medical imaging; pediatrics