Background Identification of malignancy in small breast nodules can be difficult using conventional methods, especially in patients with dense breast tissue. Advanced imaging techniques, including contrast-enhanced ultrasound (CEUS) and shear-wave elastography (SWE), may work in conjunction with Breast Imaging Reporting and Data System (BI-RADS) classification to more effectively characterize these nodules. This study aimed to evaluate the use of CEUS and SWE for differentiation of benign from malignant small (≤ 2 cm) breast nodules. Methods This retrospective study reviewed the medical records and imaging data of 302 patients who underwent evaluation for 305 small breast nodules from November 2015 to December 2019. BI-RADS classification of nodules and results from CEUS and SWE studies were retrospectively analyzed, and the diagnostic efficacy of these techniques were evaluated by comparison to pathology results. Receiver operating characteristic curves were analyzed based on CEUS patterns and shear wave velocity values of nodules. The sensitivities, specificities, positive and negative predictive values, and accuracies of BI-RADS, CEUS, SWE, and a combination of all methods for identifying benign versus malignant small breast nodules were investigated. Results CEUS was effective at diagnosing malignant nodules when at least two out of nine suspicious features were present. Receiver operating curve analysis revealed that the best cut-off value for SWE was 3.7 m/s. The BI-RADS classification of nodules was reduced by one level when both CEUS and SWE diagnosed benign BNs and was unchanged when only CEUS or SWE diagnosed benign BN, with the highest level being category 5 and the lowest level being category 3. Furthermore, when using the combined method, 75.8% (91/120) of small breast nodules with a BI-RADS category 4A classification avoided the need for coarse needle biopsies. Conclusion CEUS and SWE can be used as auxiliary methods for clarifying BI-RADS classification of BNs, and a combination of these techniques may provide more diagnostic efficacy for identifying malignancy in small breast nodules.

No abstract