Efficacy of contrast-enhanced ultrasonography and shear-wave elastography in conjunction with BI-RADS classification for diagnosis of small breast nodules

Abstract

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), could be used in conjunction with Breast Imaging Reporting and Data System (BI-RADS) classification to characterize these nodules more effectively. This study aimed to evaluate the use of CEUS and SWE for the differentiation of benign and malignant small breast nodules (maximum diameter ≤ 2 cm).Methods: This retrospective study reviewed the 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 the results of CEUS and SWE were retrospectively analyzed; the diagnostic efficacy of these techniques was evaluated by comparison with pathology results. Receiver operating characteristic curves were analyzed based on the 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 three methods for identifying benign versus malignant small breast nodules were investigated.Results: CEUS was effective in diagnosing malignant nodules when at least two of the nine suspicious features were present. Receiver operating curve analysis revealed that the best cut-off value for SWE was 3.7 m/s. For the diagnosis of benign breast nodules, the BI-RADS classification was reduced by one level when both CEUS and SWE data were used, and was unchanged when CEUS or SWE alone was used; the highest and lowest levels were category 5 and 3, respectively. Furthermore, when using the combined method, 75.8% (91/120) of small breast nodules with a BI-RADS category 4A did not need coarse needle biopsies.Conclusion: Both CEUS and SWE can be used as auxiliary methods for clarifying BI-RADS classification of breast nodules, and a combination of these techniques may provide improved diagnostic efficacy for identifying malignancy in small breast nodules.