Three-dimension quantitative CT assessment of lung volume on paired inspiratory and expiratory CT scans in chronic obstructive pulmonary disease / 中华放射学杂志

ABSTRACT

Objective To evaluate the relationship between the lung volume (LV) in inspiration and expiration,pulmonary function tests(PFT),and other CT measurements of emphysema index (EI) and mean lung density (MLD) in patients with chronic obstructive pulmonary disease (COPD).Methods Seventy-six patients with COPD were included.Three-dimension analysis was performed to obtain the following CT parameters on the inspiratory and expiratory phasesEI,MLD,LV.The ratios and differencesof MLD and LV between the two phases were calculated(ΔMLD,ΔLV,MLDex/in,LVexin).Not only the linear correlations between the lung volume parameters and PFT but also the correlations of lung volume parameters with the other CT parameters were tested by the Spearman rank correlation test and multivariant step wise regression.Results LVex/in had negative correlations with forced expiratory volume in 1 second ％ predicted [FEV1 ％,(54.32 ± 7.11)] and the ratio of forced expiratory volume in 1 second to forced vital capacity [FEV1/FVC,(49.12 ±8.01)％] (r =-0.69,-0.56,P ＜0.01),but it had the positive correlation with the ratio of residual volume to total lung capacity [RV/TLC,(58.03 ± 8.55) ％,Spearman coefficients 0.66,P ＜ 0.01].LV/exin (0.67 ± 0.12) was positively correlated with MLDex/in (0.89 ± 0.04,r =0.88,P ＜0.01).The further multivariate step wise regression denonstrated that EI,LV and MLD could introduce a regression equation with R2 =0.77 and 0.73,respectively (P ＜ 0.01).Conclusions There is an association between LVex/in and the parameters of routine PFT,which can reflect the collapsibility of lung.Moreover,LVex/in can be considered to be equivalent to MLDex/in.Taking into account the impact of scanning parameters on MLDex/in,LVex/in may play a complementary role in the assessment of pulmonary function.