Diagnostic performances of shear-wave elastography and B-mode ultrasound to differentiate benign and malignant breast lesions: the emphasis on the cutoff value of qualitative and quantitative parameters

To investigate the most effective cutoff values for shear-wave elastography (SWE) for differentiating benign and malignant breast lesions and to evaluate the diagnostic performance of quantitative and qualitative SWE in combination with B-mode ultrasound (US).209 breast lesions from 200 patients were evaluated with B-mode US and SWE. Pathologic results determined by US-guided core needle biopsy or surgical excisions were used as a reference standard. Qualitative (four-color pattern) and quantitative analyses (Emean, Emax, SD, and E ratio) were performed. The cut-off values were defined using Youden's index. The diagnostic performance of B-mode US and combination of B-mode US with four-color pattern or quantitative parameters were compared.Of the 209 breast lesions, 102 were benign and 107 were malignant. All qualitative and quantitative SWE parameters had significantly higher specificity, positive predictive value (PPV), and accuracy compared to B-mode US (p 0.001). The optimal cutoff values for the Emax, Emean, SD and E ratio were 145.7 kPa, 89.1 kPa, 11.9, and 3.84, respectively. The optimal cutoff for color pattern was between 3 and 4. Combined B-mode US and Emax had the highest improvement, from 17.65% to 98.04% for specificity and from 58.85% to 82.78% for accuracy, with a decrease in sensitivity compared with B-mode.Quantitative and qualitative SWE combined with B-mode US improved the accuracy to differentiate benign from malignant lesions. Emax (cutoff, 145.7 kPa) appeared to be the most discriminatory parameter.