CT detection of myocardial blood volume deficits: Dual-energy CT compared with single-energy CT spectra

Background The performance of dual-energy CT (DECT) for the detection of myocardial blood volume deficits has not systematically been compared with single-energy CT (SCT) spectra. Objective We evaluated the accuracy for detection of myocardial blood volume deficits in DECT and SCT compared with 99m-Tc-Sestamibi-SPECT (single-photon emission CT) during rest and stress. Methods 47 patients underwent rest/stress SPECT myocardial perfusion imaging and cardiac DECT on a dual-source CT scanner. The A- and B-tubes were operated with 140 kV and 80 kV/100 kV, respectively. DECT raw data were reconstructed by (1) only using high-energy (140 kV) CT spectra, (2) only using low-energy (80 kV/100 kV) CT spectra, (3) merging data (30% low- and 70% high-energy CT spectra), and (4) DECT-based iodine maps. Two independent, blinded observers analyzed all CT data according to each of the 4 reconstruction strategies for myocardial blood volume deficits. Results Specificity and positive predictive values were relatively similar between the 4 reconstruction strategies, with highest specificity (98%) of SCT datasets based on 140 kV for mixed perfusion deficits seen on SPECT. DECT iodine maps showed highest sensitivity, negative predictive value, and accuracy of 91%, 97%, and 93%, respectively, for mixed perfusion deficits. Analysis with receiver operating characteristics showed highest area under the curve values (0.84–0.93) with the use of DECT iodine maps in the detection of purely fixed and mixed perfusion deficits. Conclusion DECT iodine maps show superior performance for the detection of fixed and mixed perfusion deficits compared with SCT spectra.