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 the Breast Imaging Reporting and Data System (BI-RADS) classification to characterize these nodules more effectively. This retrospective study aimed to evaluate the use of CEUS and SWE for the differentiation of benign from malignant small (≤ 2 cm) breast nodules.Methods: We reviewed the medical records and imaging data of 302 patients who underwent evaluation for 305 small breast nodules from November 2015 to December 2019. The BI-RADS classification values of the nodules and the results of CEUS and SWE were retrospectively analyzed; the diagnostic efficacy of these techniques was evaluated by comparison of the pathology results. Receiver operating characteristic (ROC) curves were analyzed based on the CEUS patterns and shear-wave velocity values of the nodules. The sensitivity, specificity, positive and negative predictive values, accuracies of BI-RADS, CEUS, SWE, and a combination of all three methods for identifying benign and 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. ROC analysis revealed that the best cut-off value for SWE was at 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 were used, and remained unchanged when either one, CEUS or SWE was used; the highest and lowest levels were of 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 classification avoided the need for coarse needle biopsies.Conclusions: CEUS and SWE can be used as auxiliary methods for clarifying BI-RADS classification of the breast nodules, and a combination of these techniques may provide more diagnostic efficacy for identifying malignancy in small breast nodules.Trial registration: Retrospectively registered.