Quantitative evaluation of tissue stiffness around lesion by sound touch elastography in the diagnosis of benign and malignant breast lesions.

The purpose of our study is to assess the diagnostic performance of quantitative evaluation of tissue stiffness around lesion by Sound Touch Elastography (STE) in distinguishing between benign and malignant breast lesions. A total number of 160 breast lesions from 160 female patients were examined by STE. Resona 7 was equipped with "shell" function to measure elastic modulus values of tissue in the region of surrounding lesion quantitatively. The contours of the lesion were required to be delineated. The elastic modulus values of tissue in the region of 1mm, 2mm, and 3mm outside the boundary were acquired. The elastic modulus values included maximum elastic modulus (Emax), mean elastic modulus (Emean), minimum elastic modulus (Emin), and elastic modulus standard deviation (Esd). All lesions were confirmed by histopathology. We compared the differences of the above elastic modulus values between benign and malignant groups. Receiver operating characteristic (ROC) curve was drawn with the histological diagnostic results as the gold standard. Sensitivity and specificity were calculated to evaluate the diagnostic performance of STE. Operator consistency was also analyzed. Among the 160 lesions, 100 (62.5%) were benign and 60 (37.5%) were malignant. In the region of 1mm, 2mm, and 3mm surrounding the lesion, Emax, Emean, and Esd of malignant group were significantly higher than those of the benign group (all P<0.05). When the "shell" was 3mm, Emax had the highest AUROC value (AUROC = 0.998). Regarding the measurement of elastic modulus values, all the intra-class correlation coefficient (ICC) values of the inter-operator consistency were greater than 0.75 for Emax, Emean, and Esd. Therefore, quantitative evaluation of tissue stiffness around lesion by STE has the potential to distinguish between benign and malignant breast lesions.