title: Lung Clearance Index and Structural Lung Disease on Computed Tomography in Early Cystic Fibrosis.
abstract: BACKGROUND
  The lung clearance index is a measure of ventilation distribution derived from the multiple-breath washout technique. It has been suggested as a surrogate for chest computed tomography to detect structural lung abnormalities in individuals with cystic fibrosis (CF); however, the associations between lung clearance index and early structural lung disease are unclear.
  
  
  OBJECTIVE
  We assessed the ability of the lung clearance index to reflect structural lung disease on the basis of chest computed tomography across the entire pediatric age range.
  
  
  METHODS
  Lung clearance index was assessed in 42 infants (ages 0-2 yr), 39 preschool children (ages 3-6 yr), and 38 school-age children (7-16 yr) with CF before chest computed tomography and in 72 healthy control subjects. Scans were evaluated for CF-related structural lung disease using the Perth-Rotterdam Annotated Grid Morphometric Analysis for Cystic Fibrosis quantitative outcome measure.
  
  
  RESULTS
  In infants with CF, lung clearance index is insensitive to structural disease (κ = -0.03 [95% confidence interval, -0.05 to 0.16]). In preschool children with CF, lung clearance index correlates with total disease extent. In school-age children, lung clearance index correlates with extent of total disease, bronchiectasis, and air trapping. In preschool and school-age children, lung clearance index has a good positive predictive value (83-86%) but a poor negative predictive value (50-55%) to detect the presence of bronchiectasis.
  
  
  CONCLUSIONS
  These data suggest that lung clearance index may be a useful surveillance tool to monitor structural lung disease in preschool and school-age children with CF. However, lung clearance index cannot replace chest computed tomography to screen for bronchiectasis in this population.
authors.affiliation: 1 Telethon Kids Institute and.|2 Cystic Fibrosis Research and Treatment Centre, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ramsey
authors.affiliation: 1 Telethon Kids Institute and.|3 School of Paediatrics and Child Health, University of Western Australia, Subiaco, Australia.
authors.forename: Tim
authors.initials: T
authors.lastname: Rosenow
authors.affiliation: 1 Telethon Kids Institute and.
authors.forename: Lidija
authors.initials: L
authors.lastname: Turkovic
authors.affiliation: 4 Murdoch Children's Research Institute, Parkville, Australia.|5 Department of Respiratory Medicine, Royal Children's Hospital, Parkville, Australia.
authors.forename: Billy
authors.initials: B
authors.lastname: Skoric
authors.affiliation: 1 Telethon Kids Institute and.
authors.forename: Georgia
authors.initials: G
authors.lastname: Banton
authors.affiliation: 4 Murdoch Children's Research Institute, Parkville, Australia.|5 Department of Respiratory Medicine, Royal Children's Hospital, Parkville, Australia.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Adams
authors.affiliation: 1 Telethon Kids Institute and.
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: Simpson
authors.affiliation: 6 Department of Diagnostic Imaging and.
authors.forename: Conor
authors.initials: C
authors.lastname: Murray
authors.affiliation: 4 Murdoch Children's Research Institute, Parkville, Australia.|5 Department of Respiratory Medicine, Royal Children's Hospital, Parkville, Australia.|7 Department of Paediatrics, University of Melbourne, Parkville, Australia.
authors.forename: Sarath C
authors.initials: SC
authors.lastname: Ranganathan
authors.affiliation: 1 Telethon Kids Institute and.|8 Department of Respiratory Medicine, Princess Margaret Hospital for Children, Subiaco, Australia; and.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Stick
authors.affiliation: 1 Telethon Kids Institute and.
authors.forename: Graham L
authors.initials: GL
authors.lastname: Hall
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001987:Bronchiectasis / Q000175:diagnosis / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007223:Infant; D008168:Lung / Q000000981:diagnostic imaging / Q000502:physiology / Q000503:physiopathology*; D008171:Lung Diseases / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D009079:Mucociliary Clearance / Q000502:physiology; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed
keywords: child; cystic fibrosis; imaging; infant; multiple-breath washout