Discordance between CT measures of COPD and spirometry: Assessment of mechanistic differences

摘要: Background Many COPD patients have marked discordance between FEV1 and extent of emphysema on volumetric CT. The etiology for this is not well understood. Methods Subjects with GOLD stage I-IV from a large multicenter study (COPDGene) were arranged by percentiles %pred Three categories created using differences in percentiles: cat1 predominant airflow obstruction minimal emphysema, cat2 matched cat3 relatively obstruction. Image registration methods Jacobian determinants, anisotropy strain tensors used to assess mechanistic the groups. Regression models above as outcome variable, adjusting age, gender, (%LAA<-950HU at end inspiration), gas trapping (%LAA<-856HU expiration), thickness segmental airways (model 1), after adding mean 2). Results: FEV1 cat 1, 2, 3 was 37.9+8.7, 88.7+12.2, 49.2+26.1 respectively, 1.4+1.2, 18.9+9.8, 20.1+18.1, respectively. With 2 control, model predicted 1 better than (adjusted R2 0.63 vs. 0.45;p<0.001). In each category, (cat1: 0.49 0.44;p=0.01; cat2: 0.79 0.74;p=0.01; cat3:R2 0.91 0.90;p=0.01). Conclusions Lung elasticity might be static measures emphysema. Compared density CT, lung mechanics significantly improve prediction