Objective:

To explore the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of Breast Imaging Reporting and Data System (BI-RADS) 4a breast lesions.

Methods:

One hundred and f

orty-nine breast masses diagnosed by conventional ultrasound as BI-RADS 4a were enrolled in this study. All patients were evaluated by CEUS before core-needle biopsy or surgical pathology. CEUS characteristics included qualitative characteristics and quantitative characteristics were analyzed and compared with pathological results. Binary logistic regression analysis was used to choose the signs of malignant and revise the classification of BI-RADS. Receiver operating characteristic (ROC) curve was applied to evaluate the diagnostic efficacy of CEUS and conventional ultrasound.

Results:

Pathological results showed 112 benign and 37 malignant lesions. Irregular lesion shape after enhancement (OR=4.32) and penetrating vessels (OR=15.79) were selected by binary logistic regression analysis as signs of malignant. After CEUS

83 (55.70%) lesions were diagnosed as BI-RADS 3

57 (38.25%) were diagnosed as BI-RADS 4a and 9 (6.04%) were diagnosed as BI-RADS 4b. The cancer-to-biopsy yield was 51.52% with CEUS-based BI-RADS 4a selected as the biopsy threshold compared with 24.83% otherwise

while the biopsy rate was only 44.30% compared with 100.00% otherwise. Overall

only 2.01% of malignant lesions were misdiagnosed. The area under curve of ROC curve with thresholds of ultrasound BI-RADS 4a

CEUS-based BI-RADS 4a were 0.500 and 0.835

respectively (95% CI: 0.392-0.680

vs

0.764-0.907

P

＜0.05).

Conclusion:

CEUS could help to differentiate between malignant and benign breast lesions with ultrasound BI-RADS 4a

and reduce unnecessary biopsies and increasecancer-to-biopsy yields. However

for some BI-RADS 4a lesions that are reduced by CEUS

a comprehensive judgment should be made to reduce false negative cases.