The effects of emphysema on the correlations between airway dimensions and pulmonary function tests in COPD / 实用放射学杂志

ABSTRACT

Objective To analyze quantitatively the effects of lung inflation on the relation of airway dimensions with pulmonary function in patients with COPD.Methods 73 patients with COPD were participated in this research.All subjects would undergo CT scan when in expiration and be evaluated for the lung emphysema index(or LAA%,the percent of total lung area occupied by low at-tenuation area)and airway dimensions,including mean wall thickness (WT),the ratio of mean wall thickness with airway dimensions (WT/AD)as well as the percent of wall area (WA%)in four subsegmental bronchi(right B1,right B10,left B1,left B10).Then,all participants were divided into two groups on the basis of LAA%=1 5%,which were the mild emphysema group (n=34)and the se-vere (n=39),to compare the differences on the correlation of forced expiratory volume in 1 second (FEV1 %)with WA%,WT/AD and WT in both groups.Results There was no correlation of FEV1 % with airway dimensions in the severe emphysema group and WT in the mild group in RB10 (P >0.05).The airway dimensions of the remaining subsegmental bronchi in the mild group had a negatively relationship with FEV1 % (r=-0.382 to -0.799,P <0.05),all of which were better than the severe group (r=-0.371 to -0.687,P <0.05).Except for RB10,the remaining three indexes of airway dimensions were negatively correlated with FEV1 %, especially in RB1.For all subsegmental bronchi,the correlation between airway dimensions and FEV1 % in mild emphysema group were better than the other.Conclusion The effects of degrees in lung inflation on airway dimensions and bronchi obstruction should be taken this interaction into account during CT scan in COPD.