Diagnostic value of electric properties tomography (EPT) for differentiating benign from malignant breast lesions: comparison with standard dynamic contrast-enhanced MRI.

Objectives: To evaluate the diagnostic utility of electric properties tomography (EPT) in differentiating benign from malignant breast lesions in comparison with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

Methods: In this institutional review board-approved retrospective study, 116 consecutive patients with 141 breast lesions (50 benign and 91 malignant) underwent 3-T MRI, including 3D turbo-spin echo (TSE) sequence and standard DCE-MRI scans between January 2014 and January 2017. The lesions were segmented semi-automatically using subtraction DCE-MR images, and they were registered to the phase images from 3D TSE. The mean conductivity of the lesion was obtained from phase-based reconstruction of lesions. From the DCE-MRI, initial enhancement rate (IER) and signal enhancement ratio (SER) were calculated from signal intensity (SI) as follows: IER = (SI - SI)/SI, SER = (SI - SI)/(SI - SI). The parameters from EPT and the DCE-MRI were compared between benign and malignant lesions.

Results: There was significant difference in mean conductivity (0.14 ± 1.77 vs 1.14 ± 1.36 S/m, p < 0.0001) and SER (0.77 ± 0.28 vs 1.04 ± 0.25, p < 0.0001) between benign and malignant lesions, but not in IER (p = 0.06). Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of the mean conductivity and SER was 0.71 and 0.80, respectively, without significant difference (p = 0.15).

Conclusions: The mean conductivity of EPT was significantly different between benign and malignant breast lesions as well as kinetic parameter or SER from DCE-MRI.

Key Points: • The conductivity of malignant lesions was higher than that of benign lesions. • EPT helps differentiatie benign from malignant lesions. • Diagnostic ability of EPT was not significantly different from that of DCE-MRI.