Diagnostic Value and Reliability of Color Overlay Pattern of Shear - Wave Elastography for Assessing Palpable Breast Mass

Abstract

To evaluate the correlation between quantitative values of stiffness of palpable breast lesion and pathologic results by using shear wave elastography (SWE), and to assess SWE color overlay pattern of the palpable breast lesions and investigate association with BI-RADS category. Conventional breast US and SWE were performed in 99 women with 110 palpable breast lesions (52 benign, 58 malignant). All cases were either pathologically confirmed or showed no interval change over 6 months. Diagnostic performance, optimal cutoff value and pathological correlation for each quantitative SWE parameter were calculated by ROC curve and independent t test. Association between SWE color pattern and BI-RADS category were assessed by Chi-squared test. Of the 110 palpable breast masses, 52 masses (47.3%) were benign and 58 masses (52.7%) were malignant. Mean Emax of malignant masses (109.3 ± 75.6 kPa) was significantly higher than that of benign (26.2 ± 20.9kPa) (p < 0.001). SWE ratio between the lesion and adjacent fat was higher in malignant masses than benign, as follows; 11.3 ± 10.6 and 3.4 ± 3.1. Optimal cutoff values derived for mean Emax and SWE ratio were respectively, as follows; 45.1kPa and 5.3. SWE color pattern and both BI-RADS category and reference standard were significantly associated (p < 0.001). Also, SWE color pattern and echogenic halo around the lesion on conventional US were significantly associated (p < 0.001). The quantitative SWE features provide good diagnostic performance in palpable mass. In addition, color overlay pattern on SWE can provide diagnostic value, when added to conventional breast US findings, such as echogenic halo.