title: Lobe-based computed tomography assessment of airway diameter, airway or vessel number, and emphysema extent in relation to the clinical outcomes of COPD.
abstract: OBJECTIVE
  The aim of this study was to evaluate the relationship between computed tomography assessed lobe-based lung parameters and the clinical outcomes of patients with chronic obstructive pulmonary disease (COPD), including the frequency of exacerbation and annual change in forced expiratory volume in 1 second (FEV1).
  
  
  METHODS
  We studied 65 patients with COPD. We reconstructed computed tomography images to trace the bronchial tree from right B1 to B10 and created 3 cm circle images around the airways exactly perpendicular to the airway axis in the central, middle, and peripheral zones of the bronchi. The number of airways and vessels, airway inner diameter and area of emphysema in the circles were calculated for each segment. Then, we analyzed the relationships between the lobe-based image parameters and the frequency of exacerbation and annual decline in the FEV1. In addition, we assessed the effects of proximal airway lumen-obliterated emphysema (ALOE) on these clinical features.
  
  
  RESULTS
  The airway diameter was not associated with the frequency of exacerbation or annual decline in FEV1. Among the structural parameters, lower lobe emphysema was most associated with the frequency of exacerbation. The reductions in the number of airways and vessels in total lobe were associated with the annual decline in FEV1. The subgroup of patients with ALOE demonstrated lower FEV1 and more frequent exacerbation than those without ALOE.
  
  
  CONCLUSIONS
  Lower lobe emphysema predicts frequent COPD exacerbation, whereas the annual decline in FEV1 is associated with the number of airways and vessels in total lobe.
authors.affiliation: Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kurashima
authors.affiliation: Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Yotaro
authors.initials: Y
authors.lastname: Takaku
authors.affiliation: Radiology, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Hoshi
authors.affiliation: Radiology, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Kanauchi
authors.affiliation: Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Nakamoto
authors.affiliation: Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Takayanagi
authors.affiliation: Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yanagisawa
authors.affiliation: Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Sugita
authors.affiliation: Pathology, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kawabata
mesh_terms: D000368:Aged; D001995:Bronchography / Q000379:methods*; D018450:Disease Progression; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D012307:Risk Factors; D012720:Severity of Illness Index; D013147:Spirometry; D013997:Time Factors
keywords: acute exacerbation; chronic obstructive pulmonary disease; computed tomography; low attenuation area; pulmonary function tests