title: Longitudinal study of airway dimensions in chronic obstructive pulmonary disease using computed tomography.
abstract: OBJECTIVE
  Chest CT has been widely used for the evaluation of structural changes in lung parenchyma and airways in cross-sectional studies. There has been no report on the annual changes in airway dimensions as assessed by CT in COPD patients. The objective of this study was to investigate the annual changes in airway dimensions and lung attenuation using CT in patients with COPD and to evaluate the correlations among annual changes in CT measurements and pulmonary function.
  
  
  METHODS
  Eighty-three men with COPD had completed five annual assessments of CT scans and pulmonary function tests over 4 years. Airway dimensions of the basal segment bronchi and lung attenuation on CT images were analysed in 38 subjects in whom the same airway could be measured at least three times, including at entry and at the end of the study.
  
  
  RESULTS
  Mean annual decline in FEV(1) was 21 mL/year. Annual changes in the percentage of low attenuation areas were not significantly correlated with decline in FEV(1). On the other hand, annual changes in the percentage of wall area (WA%/year) were significantly inversely correlated with annual changes in FEV(1) (r = -0.363, P = 0.025), whereas WA%/year did not differ among severity stages at entry and did not correlate with baseline FEV(1).
  
  
  CONCLUSIONS
  The results showing that annual changes in airway thickening correlated with annual decline in air flow limitation suggests the importance of treatment of airway inflammation in COPD. CT is a useful tool for quantitative estimation not only of emphysema but also of airway lesions in longitudinal studies.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ohara
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Hirai
authors.forename: Susumu
authors.initials: S
authors.lastname: Sato
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Terada
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kinose
authors.forename: Akane
authors.initials: A
authors.lastname: Haruna
authors.forename: Satoshi
authors.initials: S
authors.lastname: Marumo
authors.forename: Michiyoshi
authors.initials: M
authors.lastname: Nishioka
authors.forename: Emiko
authors.initials: E
authors.lastname: Ogawa
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Nakano
authors.forename: Yuma
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ito
authors.forename: Hisako
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Mio
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chin
authors.forename: Shigeo
authors.initials: S
authors.lastname: Muro
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D000368:Aged; D001980:Bronchi / Q000473:pathology; D018450:Disease Progression; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed