title: Assessment of early bronchiectasis in young children with cystic fibrosis is dependent on lung volume.
abstract: OBJECTIVE
  The aim of this study was to determine whether assessment of early CT scan-detected bronchiectasis in young children with cystic fibrosis (CF) depends on lung volume.
  
  
  METHODS
  This study, approved by the hospital ethics committee, included 40 young children with CF from a newborn screened population contributing paired volume-controlled inspiratory and expiratory volumetric chest CT scans acquired under general anesthesia while clinically stable. Bronchiectasis was assessed with a semiquantitative CT scan score in inspiration and expiration, and the sensitivity of the expiratory CT scan to detect bronchiectasis was compared with the inspiratory CT scan by sensitivity and intraclass correlation coefficient analysis and Bland-Altman plots. Matched inspiratory and expiratory airway-vessel measurements were obtained in a subset of 10 children, and the relationship between lung volume and airway:vessel ratio after adjusting for age and vessel size was examined with the use of a linear regression model with generalized estimating equations. The number of visible airways in inspiration and expiration was compared in all 40 children by Wilcoxon signed rank test.
  
  
  RESULTS
  Expiratory scans had poor sensitivity (0.46) to detect bronchiectasis, underestimating disease extent (P &lt; .001). Airway:vessel ratios were consistently higher in inspiration, independent of age and vessel size (P &lt; .001), with significantly more airways visible in inspiration than in expiration, independent of age (median, 71 vs 28, respectively; P &lt; .001).
  
  
  CONCLUSIONS
  In young children with CF, radiologic assessment of early bronchiectasis with chest CT scan depends on lung volume; thus, expiratory scans may not be appropriate for evaluating bronchiectasis in this population. Lung volume during CT image acquisition should be standardized to evaluate airway dimensions in young children.
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia; School of Paediatrics and Child Health, The University of Western Australia, Perth, WA, Australia. Electronic address: lmott@ichr.uwa.edu.au.
authors.forename: Lauren S
authors.initials: LS
authors.lastname: Mott
authors.affiliation: Department of Pediatric Pulmonology and Allergology, Erasmus Medical Centre, Rotterdam, The Netherlands; Erasmus Medical Centre-Sophia Children's Hospital, Department of Radiology, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Karla G
authors.initials: KG
authors.lastname: Graniel
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia.
authors.forename: Judy
authors.initials: J
authors.lastname: Park
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia.
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: de Klerk
authors.affiliation: Queensland Children's Medical Research Institute, University of Queensland, Brisbane, QLD, Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Sly
authors.affiliation: Department of Diagnostic Imaging, Princess Margaret Hospital for Children, Perth, WA, Australia.
authors.forename: Conor P
authors.initials: CP
authors.lastname: Murray
authors.affiliation: Department of Pediatric Pulmonology and Allergology, Erasmus Medical Centre, Rotterdam, The Netherlands; Erasmus Medical Centre-Sophia Children's Hospital, Department of Radiology, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Harm A W M
authors.initials: HAWM
authors.lastname: Tiddens
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia; School of Paediatrics and Child Health, The University of Western Australia, Perth, WA, Australia; Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, WA, Australia.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Stick
mesh_terms: D001987:Bronchiectasis / Q000000981:diagnostic imaging* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000150:complications*; D042241:Early Diagnosis; D006801:Humans; D007223:Infant; D008168:Lung / Q000473:pathology*; D009929:Organ Size; D012119:Respiration; D014057:Tomography, X-Ray Computed