CT emphysema distribution : relationship to clinical features in a cohort of smokers

¹ MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh
² Medical Physics
³ Radiology, the Royal Infirmary of Edinburgh, Scotland, United Kingdom

^* To whom correspondence should be addressed. E-mail: w.macnee{at}ed.ac.uk.

	Abstract

CT scanning allows precise assessment of both the extent and distribution of emphysema. There has been little work on the relation between the distribution of emphysema and clinical features of the disease. We investigated the association between clinical features and distribution of emphysema.

One hundred and twenty nine patients with smoking-related COPD had CT assessment of the extent and distribution of their emphysema (core/rind and upper/lower zone predominance).

Emphysema was predominantly in the upper-core zone and this distribution was related to the extent of disease. Core predominance was associated with lower FEV₁, FEV₁/FVC ratio and BMI; higher BODE index and MRC dyspnoea score. Upper zone predominance was associated with female sex and an increased total SGRQ. Using multiple linear regression age, sex and whole lung emphysema severity were independently associated with core/rind distribution; while sex and whole lung emphysema severity were independently related to upper/lower distribution.

Distribution of emphysema related best to clinical features when divided into core/rind predominance. However, these effects were not independent of the extent of emphysema. Increasing age and female sex were related to disease distribution independent of emphysema severity. These findings may be related to differences in development of emphysema.