Comparative study of lumbar bone mineral content using DXA and CT Hounsfield unit values in chest CT

Abstract

Background: Bone mineral content (BMC) values in certain bones and changes in BMC over time are key features for diagnosing osteoporosis. This study examined those features using morphometric texture analysis in chest computational tomography (CT) by comparing a dual-energy X-ray absorptiometry (DXA)-based BMC. An accessible approach for screening osteoporosis was suggested by accessing BMC using only Hounsfield units (HU). Methodology: The study included a total of510 cases (255 patients) acquired between May 6, 2012, and June 30, 2020, at asingle institution. Two cases were associated with two chest CT scans from onepatient with a scan interval of over two years, and each scan was followed soonafter by a DXA scan. Axial cuts of the first lumbar vertebra in CT andDXA-based L1 BMC values were corrected for each case. The maximum trabeculararea was selected from the L1 spine body, and 45 texture features wereextracted from the region using gray-level co-occurrence matrices. A regressionmodel was employed to estimate the absolute BMC value in each case using 45features. Also, an additional regression model was used to estimate the changein BMC between two scans for each patient using 90 features from thecorresponding cases. Results: The correlation coefficient (CC) and mean absoluteerror (MAE) between estimates and DXA references were obtained for theevaluation of regressors. In the case of the BMC estimation, CC and MAE were0.754 and 1.641 (g). In the case of the estimation of change in BMC, CC and MAEwere 0.680 and 0.528 (g). Conclusion: The modality using morphometric texture analysiswith CT HUs can indirectly help screening osteoporosis because it providesestimates of BMC and BMC change that show moderate positive correlations withDXA measures.