Evaluation stiff rim sign in breast lesions by shear wave elastography with quantative values

Abstract

Objective To evaluate the diagnostic performance of shear wave elastography (SWE) with quantitative analysis and qualitative analysis of stiff rim sign between benign and malignant breast lesions. Methods Sixty-five female patients(65 lesions) underwent breast surgery or aspiration biopsy at the Second Affiliated Hospital of Zhejiang University were included. Elastic modulus of breast lesions and its rim in 1 mm, 2 mm, 3 mm were quantitive analyzed by SWE before surgery or aspiration biopsy, Stiff rim sign was observed at the same time. Then, the areas of receiver operating characteristic curves(AUC) of quantitative parameters of SWE and stiff rim sign were calculated to assess their clinical values in differentiating benign and malignant breast lesions, and the correlation between them was evaluated. Afterwards, BI-RADS category was adjusted according to the optimal parameters combining the performance of SWE feature and conventional US features, which could be used to evatulate the diagnostic effectiveness in differentiating benign and malignant breast lesions. Results The pathological results demonstrated 32 benign cases and 33 malignant cases in all patients.The maximum cut-off point of BI-RADS category was set between 4a and 4b.AUC value was 0.935(0.845-0.981), while the sensitivity and specificity were 84.8% and 90.6%, respectively.Maximum elasticity of 2 mm(E2Smax) area surrounding the malignant lesions were significantly higher than those in benign lesions(P=0.001). Among all quantitative SWE features, E2Smax showed the highest AUC(0.773), with sensitivity of 78.8% and specificity of 71.9%. In addition, the stiff rim sign as qualitative parameter showed the highest AUC(0.800), with sensitivity 81.8% and specificity 78.1%. The correlation coefficient between E2Smax and stiff rim sign was 0.63, which was regarded as moderate correlation. the AUC of combination of stiff rim sign or E2Smax and conventional US features was 0.937 and 0.902, and the sensitivities were 81.8%, 93.9%, the specificities were 90.6% and 75.0%. Conclusions SWE features, especially E2Smax and hard rim sign are found moderate correlation, and can improve a more accurate diagnosis in differentiating benign and malignant breast lesions combining with conventional US features. Key words: Ultrasonography; Breast neoplasms; Elasticity Imaging Techniques; Stiff rim sign