Value of shear wave elastography during second-look breast ultrasonography for suspicious lesions on magnetic resonance imaging

Purpose: This study aimed to determine whether the addition of shear wave elastography (SWE) helps to improve diagnostic performance of second-look ultrasonography (SLUS) for suspicious lesions on magnetic resonance imaging (MRI). Methods: We retrospectively reviewed 76 breast lesions in 62 patients who underwent SLUS and SWE for suspicious lesions on MRI from August 2017 to November 2019. The six-point color scale (E_col) and four-type color pattern (E_pattern) were used for qualitative evaluation, and the mean (E_mean) and maximum elasticity (E_max) and standard deviation of elasticity (E_SD) were recorded as quantitative parameters. Clinical and imaging findings between benign and malignant lesions were compared, and the diagnostic performance was assessed using receiver-operating characteristic (ROC) analysis. Results: The biopsies revealed 52 benign and 24 malignant lesions. Of all SWE parameters, only E_SD was significantly higher in malignant lesions than in benign lesions (p = 0.012). The sensitivity of B-mode US was 100%, but the specificity was low (19.2%). Using SWE parameters to classify lesions improved specificity at the expense of sensitivity. When lesions assigned to Breast Imaging Reporting and Data System (BI-RADS) category 3 or 4a were reclassified considering each SWE parameter, the area under the ROC curve (AUC) and sensitivity increased. The AUC of the US BI-RADS category adjusted by E_SD was higher than that of B-mode US BI-RADS (0.770 vs. 0.746). Conclusion: SWE parameters, and especially E_SD, may play a complimentary role in improving the specificity of SLUS. However, the decision to omit biopsies for suspicious lesions with soft features should be made with caution.