title: Prevalence of tracheal collapse in an emphysema cohort as measured with end-expiration CT.
abstract: OBJECTIVE
  To retrospectively investigate the prevalence of tracheal collapse in an emphysema cohort. The occurrence of a large degree of tracheal collapse may have important implications for the clinical management of respiratory symptoms and air trapping in patients with emphysema.
  
  
  METHODS
  Paired full-inspiratory and end-expiratory thin-section volumetric computed tomographic scans were available for 1071 long-term smokers with clinically and physiologically confirmed emphysema. The percentage reduction in the cross-sectional tracheal luminal area from full-inspiration to end-expiration was automatically computed at 2.5-mm intervals along the centerline of the trachea using customized software.
  
  
  RESULTS
  Maximal tracheal collapse did not follow a normal distribution in the emphysema cohort (P < .0001, skewness/kurtosis tests for normality); the median collapse was 18% (intraquartile range, 11%-30%). Statistically significant differences were found in the distribution of maximal collapse by gender (P < .005, Wilcoxon rank sum test). Overall, 10.5% of men and 17.1% of women showed evidence of tracheomalacia on the basis of the criterion of a reduction of 50% or greater in cross-sectional tracheal luminal area at end-expiration.
  
  
  CONCLUSIONS
  This study offers insights into the prevalence of tracheal collapse in a cohort of patients with emphysema; future work is needed to determine the possible relationship between tracheal collapse and air trapping in subjects with emphysema.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA 90024-2926, USA. rochs@mednet.ucla.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Ochs
authors.forename: Iva
authors.initials: I
authors.lastname: Petkovska
authors.forename: Hyun J
authors.initials: HJ
authors.lastname: Kim
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Abtin
authors.forename: Matthew
authors.initials: M
authors.lastname: Brown
authors.forename: Jonathan
authors.initials: J
authors.lastname: Goldin
mesh_terms: D000328:Adult; D000368:Aged; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D004646:Emphysema / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000706:statistics & numerical data*; D014135:Tracheal Stenosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*