title: Correlation between airflow limitation and airway dimensions assessed by multidetector CT in asthma.
abstract: BACKGROUND
  Asthma is characterized by variable airflow obstruction and airway wall thickening. Multidetector-row computed tomography (MDCT) is useful for the evaluation of airway wall structural changes in asthma. The objective of the study is to assess the relationship between airflow limitation and airway dimensions from the third to fifth generation bronchi in asthma using MDCT.
  
  
  METHODS
  Thirty-eight subjects with asthma underwent MDCT to measure the airway wall area (WA) and luminal area (Ai), WA and Ai corrected by body surface area (BSA), up to the fifth generation of the apical bronchus (B1) and the posterior basal bronchus (B10) of the right lung.
  
  
  RESULTS
  WA/BSA, WA percentage (WA%) and Ai/BSA in the fifth generation were significantly correlated with forced expiratory volume in 1 s (FEV(1))% predicted. The correlation coefficients between WA% and FEV(1)% predicted increased when tracking the airways from the third to the fifth generation (r=-0.25, p>0.05; r=-0.40, p<0.01; r=-0.63, p<0.001 for B1; r=-0.23, p>0.05; r=-0.47, p<0.01; r=-0.69, p<0.001 for B10). At the generation 5, WA% was greater and Ai/BSA was smaller in severe asthma than mild-to-moderate asthma.
  
  
  CONCLUSIONS
  These results suggest that airway flow limitation in asthma is closely related to the more distal airways (third to fifth generation).
authors.affiliation: Department of Respiratory Medicine, Atami Hospital, International University of Health and Welfare, Atami, Japan. hoshino@iuhw.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Hoshino
authors.forename: Shin
authors.initials: S
authors.lastname: Matsuoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Handa
authors.forename: Teruomi
authors.initials: T
authors.lastname: Miyazawa
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yagihashi
mesh_terms: D000403:Airway Resistance / Q000502:physiology*; D001249:Asthma / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001830:Body Surface Area; D001980:Bronchi / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012129:Respiratory Function Tests; D020545:Respiratory Mucosa / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed