title: Air trapping on chest CT is associated with worse ventilation distribution in infants with cystic fibrosis diagnosed following newborn screening.
abstract: BACKGROUND
  In school-aged children with cystic fibrosis (CF) structural lung damage assessed using chest CT is associated with abnormal ventilation distribution. The primary objective of this analysis was to determine the relationships between ventilation distribution outcomes and the presence and extent of structural damage as assessed by chest CT in infants and young children with CF.
  
  
  METHODS
  Data of infants and young children with CF diagnosed following newborn screening consecutively reviewed between August 2005 and December 2009 were analysed. Ventilation distribution (lung clearance index and the first and second moment ratios [LCI, M(1)/M(0) and M(2)/M(0), respectively]), chest CT and airway pathology from bronchoalveolar lavage were determined at diagnosis and then annually. The chest CT scans were evaluated for the presence or absence of bronchiectasis and air trapping.
  
  
  RESULTS
  Matched lung function, chest CT and pathology outcomes were available in 49 infants (31 male) with bronchiectasis and air trapping present in 13 (27%) and 24 (49%) infants, respectively. The presence of bronchiectasis or air trapping was associated with increased M(2)/M(0) but not LCI or M(1)/M(0). There was a weak, but statistically significant association between the extent of air trapping and all ventilation distribution outcomes.
  
  
  CONCLUSIONS
  These findings suggest that in early CF lung disease there are weak associations between ventilation distribution and lung damage from chest CT. These finding are in contrast to those reported in older children. These findings suggest that assessments of LCI could not be used to replace a chest CT scan for the assessment of structural lung disease in the first two years of life. Further research in which both MBW and chest CT outcomes are obtained is required to assess the role of ventilation distribution in tracking the progression of lung damage in infants with CF.
authors: Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Australia. grahamh@ichr.uwa.edu.au
authors: Graham L
authors: GL
authors: Hall
authors: Karla M
authors: KM
authors: Logie
authors: Faith
authors: F
authors: Parsons
authors: Sven M
authors: SM
authors: Schulzke
authors: Gary
authors: G
authors: Nolan
authors: Conor
authors: C
authors: Murray
authors: Sarath
authors: S
authors: Ranganathan
authors: Phil
authors: P
authors: Robinson
authors: Peter D
authors: PD
authors: Sly
authors: Stephen M
authors: SM
authors: Stick
authors: Luke
authors: L
authors: Berry
authors: Luke
authors: L
authors: Garratt
authors: John
authors: J
authors: Massie
authors: Lauren
authors: L
authors: Mott
authors: Srinivas
authors: S
authors: Poreddy
authors: Shannon
authors: S
authors: Simpson
mesh_terms: D000388:Air; D018893:Bronchoalveolar Lavage / Q000009:adverse effects; D002648:Child; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D055370:Lung Injury / Q000209:etiology* / Q000473:pathology; D008297:Male; D015997:Neonatal Screening; D013902:Radiography, Thoracic; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014691:Ventilation