rss
Thorax 2000;55:198-204 doi:10.1136/thorax.55.3.198
  • Original article

Airflow obstruction in bronchiectasis: correlation between computed tomography features and pulmonary function tests

  1. H R Robertsa,
  2. A U Wellsa,
  3. D G Milneb,
  4. M B Rubensa,
  5. J Kolbeb,
  6. P J Colea,
  7. D M Hansella
  1. aRoyal Brompton Hospital, Sydney Street, London SW3 6NP, UK, bGreen Lane Hospital, Auckland, New Zealand
  1. Dr A U Wells
  • Received 15 March 1999
  • Revision requested 11 June 1999
  • Revised 3 November 1999
  • Accepted 25 November 1999

Abstract

BACKGROUND An obstructive defect is usual in bronchiectasis, but the pathophysiological basis of airflow obstruction remains uncertain. High resolution computed tomographic (CT) scanning now allows quantitation of static morphological abnormalities, as well as dynamic changes shown on expiratory CT scans. The aim of this study was to determine which static and dynamic structural abnormalities on the CT scan are associated with airflow obstruction in bronchiectasis.

METHODS The inspiratory and expiratory features on the CT scan of 100 patients with bronchiectasis undergoing concurrent lung function tests were scored semi-quantitatively by three observers.

RESULTS On univariate analysis the extent and severity of bronchiectasis, the severity of bronchial wall thickening, and the extent of decreased attenuation on the expiratory CT scan correlated strongly with the severity of airflow obstruction; the closest relationship was seen between decreased forced expiratory volume in one second (FEV1) and the extent of decreased attenuation on the expiratory CT scan (R s = –0.55, p<0.00005). On multivariate analysis bronchial wall thickness and decreased attenuation were consistently the strongest independent determinants of airflow obstruction. The extent of decreased attenuation was positively associated with the severity of bronchial wall thickness, but was not independently linked to gas transfer levels. Endobronchial secretions seen on CT scanning had no functional significance; the severity of bronchial dilatation was negatively associated with airflow obstruction after adjustment for other morphological features.

CONCLUSIONS These findings indicate that airflow obstruction in bronchiectasis is primarily linked to evidence of intrinsic disease of small and medium airways on CT scanning and not to bronchiectatic abnormalities in large airways, emphysema, or retained endobronchial secretions.

Footnotes

    This Article

    1. Abstract
    2. Full text
    3. PDF

    Register for free content

    The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.