Measurement of myocardial extracellular volume using cardiac dual-energy computed tomography in patients with ischaemic cardiomyopathy: a comparison of different methods.

To clarify the consistency and efficiency of four methods for myocardial extracellular volume (ECV) measurement (manual method using dual-energy iodine [manual ECV], manual method using subtraction [manual ECV], automatic ECV, automatic ECV) in patients with ischaemic cardiomyopathy. Fifty patients with ischaemic cardiomyopathy who underwent coronary computed tomography angiography (CCTA) following dual-energy computed tomography (CT) with late iodine enhancement (LIE-DECT) were included. LIE with ischaemic patterns representing scarring could be detected using iodine maps in all patients. The global and remote ECVs of non-scarred myocardium were measured using four methods (manual ECV, automatic ECV, manual ECV, and automatic ECV). The consistency and time cost of the four methods were analysed. There were no significant differences in the mean global ECVs or remote ECVs among the four methods (p > 0.05). ECV resulted in a lower Bland-Altman limit of agreement than that of ECV for both global and remote measurements. Intraclass correlation coefficients of the automatic and manual ECV measurements demonstrated better concordance (0.804 and 0.859, respectively) than those of automatic and manual ECV (0.607 and 0.669, respectively) for both global and remote measurements. The measurement time for automatic ECV was less than that for manual ECV for both global and remote ECV measurements (all p < 0.001). ECV measurement using dual-energy iodine yielded good concordance, and the automatic method has the advantages of being simple and convenient, which can become a useful tool for quantification of myocardial fibrosis.