Airway dimensions and pulmonary function in chronic obstructive pulmonary disease and bronchial asthma
Article first published online: 21 DEC 2011
© 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology
Volume 17, Issue 1, pages 79–86, January 2012
How to Cite
KURASHIMA, K., HOSHI, T., TAKAYANAGI, N., TAKAKU, Y., KAGIYAMA, N., OHTA, C., FUJIMURA, M. and SUGITA, Y. (2012), Airway dimensions and pulmonary function in chronic obstructive pulmonary disease and bronchial asthma. Respirology, 17: 79–86. doi: 10.1111/j.1440-1843.2011.02052.x
- Issue published online: 21 DEC 2011
- Article first published online: 21 DEC 2011
- Accepted manuscript online: 24 AUG 2011 11:40AM EST
- Received 18 January 2011; invited to revise 4 March 2011, 27 May 2011; revised 3 May 2011, 30 May 2011; accepted 8 June 2011 (Associate Editor: Robert Young).
- airway luminal area;
- airway wall;
- computed tomography;
- multiplanar reconstruction;
- small airway
Background and objective: COPD and bronchial asthma are chronic airway diseases with a different pathogenesis. Comparisons of differences in airway calibre by bronchial generation between these diseases and their importance to pulmonary function have not been fully studied. We investigated airway calibre and wall thickness in relation to pulmonary function in patients with asthma, COPD, asthma plus emphysema and normal subjects using CT.
Methods: Sixty-three asthmatic patients, 46 COPD, 23 patients with asthma plus emphysema and 61 control subjects were studied cross-sectionally. We used a software with curved multiplanar reconstruction to measure airway dimensions from 3rd- to 6th-generation bronchi of the right lower posterior bronchus.
Results: Patients with COPD had increased wall thickness, but the airway was not narrow from the 3rd-(subsegmental) to 6th-generation bronchi. Mean bronchial inner diameter (Di) of 3rd- to 6th-generation bronchi in patients with asthma or asthma plus emphysema was smaller than that of COPD patients and normal subjects. Airway luminal area (Ai) of 5th-generation bronchi most closely correlated with pulmonary function in patients with stable asthma. Although Di was similar in patients with asthma and asthma plus emphysema, the Ai of 6th-generation bronchi correlated significantly with pulmonary function in patients with asthma plus emphysema.
Conclusions: Airway calibre in asthma may be smaller than in COPD. Airflow limitations correlated more closely with peripheral Ai in patients with asthma plus emphysema than in patients with asthma alone.