title: Tracking Lung Clearance Index and chest CT in mild cystic fibrosis lung disease over a period of three years.
abstract: BACKGROUND
  Lung disease remains the main cause of morbidity and mortality in patients with Cystic Fibrosis (CF). To detect lung disease before clinical symptoms become apparent, sensitive tools are essential. Spirometry is used for monitoring, but the FEV1 remains frequently normal throughout childhood. The Lung Clearance Index (LCI) calculated from Multiple Breath Washout (MBW) was introduced at the CF centre Innsbruck in 2007 for assessing ventilation inhomogeneity in patients with mild lung disease. We hypothesized that LCIs in 2007 are of prognostic value for the presence or absence of structural lung changes in later years.
  
  
  METHODS
  Between 2007 and 2010 MBW, spirometry and ultra-low-dose HR-CT were prospectively tracked in 36 patients (6-53 years) with a mean FEV1 ≥ 80% predicted in 2007.
  
  
  RESULTS
  At study start the majority of patients had abnormal CT scores and LCI results. While CT and spirometry remained largely stable throughout the study, LCI results slightly improved but still correlated with CT scores in 2010. LCI results in 2007 correlated with CT scores in 2010 while FEV1 did not. In 86% the LCI value in 2007 was indicative for the presence or absence of structural lung changes in 2010.
  
  
  CONCLUSIONS
  The LCI is a sensitive tool for detecting and tracking pulmonary changes. Extended structural changes are unlikely if the LCI is normal. The LCI has the potential to be used for monitoring the progression of early CF lung disease and assessing the effect of treatment in both clinical care and research settings.
authors.affiliation: Department of Paediatrics and Research Institute, Marien-Hospital Wesel gGmbH, Pastor Janßen Straße 8-38, 46483 Wesel, Germany. Electronic address: susanne.fuchs@prohomine.de.
authors.forename: Susanne I
authors.initials: SI
authors.lastname: Fuchs
authors.affiliation: Department of Paediatrics and Research Institute, Marien-Hospital Wesel gGmbH, Pastor Janßen Straße 8-38, 46483 Wesel, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Gappa
authors.affiliation: Department of Paediatrics, Medical University Innsbruck, CF Centre Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Eder
authors.affiliation: Department of Radiology, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria.
authors.forename: Karin M
authors.initials: KM
authors.lastname: Unsinn
authors.affiliation: Department of Paediatrics, Medical University Innsbruck, CF Centre Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria.
authors.forename: Gratiana
authors.initials: G
authors.lastname: Steinkamp
authors.affiliation: Department of Paediatrics, Medical University Innsbruck, CF Centre Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Ellemunter
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005540:Forced Expiratory Flow Rates / Q000502:physiology; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013147:Spirometry / Q000379:methods; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Bhalla-score; Lung Clearance Index; Mild Cystic Fibrosis lung disease; Multiple Breath Washout; Ultra-low-dose chest computed tomography