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 ± 3.90 vs. 10.69 ± 1.88 in 100 μg/cm3, p = 0.015; ECV: 31.35 ± 2.53% vs. 26.62 ± 2.69%, p < 0.001). In histogram analyses, kurtosis was higher in NIDCM than in controls (0.47 ± 0.46 vs. 1.26 ± 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.