Objective: To explore the value of the diagnostic performance of scoring by shear wave elastography (SWE) combined with contrast-enhanced ultrasound (CEUS) with respect to differentiating benign and malignant in BI-RADS 4 breast nodules with different sizes. Methods: From August 2020 to October 2021

a total of 167 BI-RADS 4 breast nodules in 158 patients were collected from the First Hospital of Shanxi Medical University were divided into large size group (＞20 mm) and small size group (≤20 mm)

Both SWE and CEUS were performed

SWE and CEUS scoring alone and combined scoring were built in each nodule. The pathological finings were utilized as the gold standard

receiving operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of the separate scoring and combined scoring for discrimination between benign and malignant breast lesions. Results: In large size group

area under the ROC curve(AUC) of SWE/CEUS scoring alone was was 0.786/0.820

and the diagnostic sensitivity

specificity

accuracy

positive predictive value (PPV) and Negative predictive value (NPV) were 79.5%/81.8%

68.7%/75.0%

76.3%/78.9%

79.5%/81.8% and 71.9%/75.0%

respectively; There was no significant difference between the SWE alone score and the CEUS alone score (Z=0.537

P>0.05). when the cut-off value of combined scoring was 6.5 points

the AUC was 0.885

95% confidence interval (CI) was 0.791 to 0.947

and the sensitivity

specificity

accuracy

PPV and NPV were 88.6%

87.5%

88.2%

88.6% and 84.8%

respectively

which were higher than scoring alone

and the differences had statistical significance (Z=2.153/2.287

P<0.05) . In small size group

the AUC of SWE/CEUS scoring alone was 0.730/0.778

and the diagnostic sensitivity

specificity

accuracy

PPV and NPV were 61.0%/70.7%

68.0%/70.0%

64.8%/69.2%

61.0%/65.1% and 68.0%/72.9%

respectively; There was no significant difference between the SWE alone score and the CEUS alone score (Z=0.688

P>0.05). when cut-off value of the combined scoring was 5.5 points

the AUC was 0.868

95% CI was 0.781 to 0.930

and the diagnostic sensitivity

specificity

accuracy

PPV and NPV were 87.8%

84.0%

86.8%

83.7% and 89.6%

respectively

which were higher than scoring alone

and the differences had statistical significance (Z=3.040/2.746

P<0.05). Conclusion: Scoring by SWE combined with CEUS has a high diagnostic value for differentiating benign from malignant BI-RADS 4 breast nodules of different sizes

especially for small nodules

which the diagnostic cut-off point should be appropriately reduced

can effectively reduce unnecessary preoperative biopsies to some extent and improve diagnostic accuracy.