title: Airway wall area derived from 3-dimensional computed tomography analysis differs among lung lobes in male smokers.
abstract: BACKGROUND
  It is time-consuming to obtain the square root of airway wall area of the hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10), a comparable index of airway dimensions in chronic obstructive pulmonary disease (COPD), from all airways of the whole lungs using 3-dimensional computed tomography (CT) analysis. We hypothesized that √Aaw at Pi10 differs among the five lung lobes and √Aaw at Pi10 derived from one certain lung lobe has a high level of agreement with that derived from the whole lungs in smokers.
  
  
  METHODS
  Pulmonary function tests and chest volumetric CTs were performed in 157 male smokers (102 COPD, 55 non-COPD). All visible bronchial segments from the 3rd to 5th generations were segmented and measured using commercially available 3-dimensional CT analysis software. √Aaw at Pi10 of each lung lobe was estimated from all measurable bronchial segments of that lobe.
  
  
  RESULTS
  Using a mixed-effects model, √Aaw at Pi10 differed significantly among the five lung lobes (R(2) = 0.78, P<0.0001). The Bland-Altman plots show that √Aaw at Pi10 derived from the right or left upper lobe had a high level of agreement with that derived from the whole lungs, while √Aaw at Pi10 derived from the right or left lower lobe did not.
  
  
  CONCLUSIONS
  In male smokers, CT-derived airway wall area differs among the five lung lobes, and airway wall area derived from the right or left upper lobe is representative of the whole lungs.
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan; Respiratory Care Center, University Medical Center, Ho Chi Minh City, Vietnam.
authors.forename: Nguyen Van
authors.initials: NV
authors.lastname: Tho
authors.affiliation: Respiratory Care Center, University Medical Center, Ho Chi Minh City, Vietnam.
authors.forename: Le Thi Huyen
authors.initials: le TH
authors.lastname: Trang
authors.affiliation: Department of Medical Statistics, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan; Health Administration Center, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Ogawa
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ryujin
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Kanda
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakagawa
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Goto
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Fukunaga
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Higami
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Ruriko
authors.initials: R
authors.lastname: Seto
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Nagao
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Oguma
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamaguchi
authors.affiliation: Respiratory Care Center, University Medical Center, Ho Chi Minh City, Vietnam.
authors.forename: Le Thi Tuyet
authors.initials: le TT
authors.lastname: Lan
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Nakano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi / Q000473:pathology / Q000503:physiopathology*; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D012129:Respiratory Function Tests / Q000379:methods; D012907:Smoking / Q000009:adverse effects*