DECT-derived PBV heterogeneity in a general population sample: The MESA Lung Study

Abstract

Rationale: Increased heterogeneity (coefficient of variation: CV) of dual energy CT (DECT)-derived pulmonary perfused blood volume (PBV), a surrogate for pulmonary perfusion, is reversible with Sildenafil in emphysema-susceptible smokers. We hypothesize that inflammation-associated PBV reduction inhibits repair. Here, we assess PBV-CV in a general population sample at the 6 centers of the Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study.

Methods: Participants were 45-85yrs without clinical cardiovascular disease in 2000-02. Non-contrast full inspiratory CT, iodine-enhanced DECT (functional residual capacity) and spirometry were performed. Voxel-based PBV was calculated by material decomposition, and PBV-CV was assessed for each of 60x60x40 regions comprising the lung field. % emphysema (%emp: voxels <-950HU) was assessed on non-contrast CTs. Generalized linear regression adjusted for age, sex, race/ethnicity, height, weight, cigarette smoking status, pack-years, site, & education.

Results: Valid PBV-CV measures were available for 686 participants (mean age, 71 (range: 59-94)); 45% female, 39% White, 29% Black; 18% Hispanic and 14% Asian; 50% ever smokers. Mean PBV-CV was 65% (SD 4%). PBV-CV showed no sex differences, minor race/ethnicity differences and a positive correlation with age (p<.001). In adjusted analyses, PBV-CV was inversely correlated to FEV1 (p<.001) for participants with %emp > upper-limit-of-normal and was inversely correlated to FEV1/FVC (p<.001). PBV-CV was positively associated with %emp (p<.001).

Conclusions: These data demonstrate the significant relationships between pulmonary circulation status, population characteristics and hallmarks of smoking-associated lung disease.