title: Regional bronchodilator response assessed by computed tomography in chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  The reliability of CT assessment of regional bronchodilation is not universally accepted. In this study, using our proprietary 3D-CT software, we first examined airway inner luminal area (Ai) before and after inhalation of SFC in a group of COPD patients and then evaluated the same parameters for two sets of CT data obtained from clinically stable subjects with no intervention.
  
  
  METHODS
  We conducted CT at deep inspiration and pulmonary function tests before and one week after inhalation of SFC in 23 COPD patients. As a non-intervention group, we used two sets of CT data obtained with one-year interval in another group of subjects who demonstrated stable pulmonary function (n=8). We measured Ai at the mid-portions of 3rd to 6th generation in 8 bronchi of the right lung, a total of 32 identical sites before and after intervention.
  
  
  RESULTS
  The average bronchodilation at all sites (ΔAi%: 28.2 ± 4.1 (SE)%) (r=0.65, p<0.001) and that of each generation significantly correlated with % improvement of FEV1 (ΔFEV1%), which increased from 1.40 ± 0.10 L to 1.58 ± 0.10 L. When subjects were classified into two groups in terms of mean ΔFEV1%, even the poor responders (ΔFEV1% <14% above baseline, n=13) displayed significantly larger ΔAi% compared with the non-intervention group (19.1 ± 4.6% versus 2.1 ± 3.9%). Inter-observer variability for overall ΔAi% was within acceptable levels.
  
  
  CONCLUSIONS
  CT can reliably detect the regional bronchodilation in 3rd to 6th generation airways when ΔFEV1 is as small as 180 ml on average. This study was registered in the UMIN Clinical Trials Registry (UMIN-CTR) system (http://www.umin.ac.jp/. No. UMIN 000002668).
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Kaoruko
authors: K
authors: Shimizu
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Hironi
authors: H
authors: Makita
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Masaru
authors: M
authors: Hasegawa
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Hirokazu
authors: H
authors: Kimura
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Satoshi
authors: S
authors: Fuke
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Katsura
authors: K
authors: Nagai
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Takayuki
authors: T
authors: Yoshida
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Masaru
authors: M
authors: Suzuki
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Satoshi
authors: S
authors: Konno
authors: Department of Biostatistics, Hokkaido University Graduate School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan.
authors: Yoichi M
authors: YM
authors: Ito
authors: First Department of Medicine, Hokkaido University School of Medicine, N-15 W-7, Kita-Ku, Sapporo 060-8638, Japan. Electronic address: ma-nishi@med.hokudai.ac.jp.
authors: Masaharu
authors: M
authors: Nishimura
mesh_terms: D000280:Administration, Inhalation; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi; D001993:Bronchodilator Agents / Q000494:pharmacology*; D005260:Female; D000068297:Fluticasone-Salmeterol Drug Combination / Q000494:pharmacology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D001993:Bronchodilator Agents; D000068297:Fluticasone-Salmeterol Drug Combination
keywords: Bronchodilation; Computed tomography; Pulmonary function; Salmeterol/fluticasone propionate combination