Quantitative evaluation of non-ischemic dilated cardiomyopathy by late iodine enhancement using rapid kV switching dual-energy computed tomography: A feasibility study.

OBJECTIVES: The aim of this study was to evaluate the feasibility of myocardial iodine density and extracellular volume fraction (ECV) from delayed iodine density images using dual-energy computed tomography (DECT) for differentiation between non-ischemic dilated cardiomyopathy (NIDCM) patients and normal subjects. METHODS: Forty-six subjects were imaged, including 35 normal subjects and 11 patients with NIDCM. All subjects underwent myocardial delayed enhancement (MDE) imaging on rapid-kVp switching DECT. Global and segmental iodine density and ECV were calculated from MDE images. Histogram analysis was also performed. Receiver-operator characteristic (ROC) analysis was used to determine the cut-off value and diagnostic performances in differentiating NIDCM patients from normal subjects. RESULTS: Global iodine density and ECV were significantly higher in NIDCM compared with normal controls (iodine: 14.19 ±â€¯3.90 vs. 10.69 ±â€¯1.88 in 100 µg/cm3, p = 0.015; ECV: 31.35 ±â€¯2.53% vs. 26.62 ±â€¯2.69%, p < 0.001). In histogram analyses, kurtosis was higher in NIDCM than in controls (0.47 ±â€¯0.46 vs. 1.26 ±â€¯0.88, p < 0.001). On segmental analysis, ECV showed higher values in NIDCM than in controls for all segments. ECV could differentiate between normal myocardium and NIDCM with 91.0% sensitivity and 86.0% specificity at a cut-off of 28.82% (area under the curve of ROC, 0.906). Iodine density could differentiate between normal myocardium and NIDCM with 91% sensitivity and 60% specificity at a cut-off of 11.18 (area under the curve of ROC, 0.812). CONCLUSIONS: Iodine density and ECV values from DECT may provide indices offering high diagnostic accuracy for discriminating between NIDCM and normal myocardium.