The value of conventional ultrasound combined with contrast-enhanced ultrasound in the diagnosis of BI-RADS category 4 small breast nodules / 中华超声影像学杂志

ABSTRACT

Objective:To evaluate the value of conventional ultrasound(US) combined with contrast-enhanced ultrasound(CEUS) in the diagnosis of Breast Imaging Reporting and Data System( BI-RADS) category 4 small(≤ 2 cm) breast nodules.Methods:A total of 175 breast nodules in 175 patients from Fujian Cancer Hospital between September 2015 and August 2018 classified as BI-RADS category 4 breast nodules with maximum diameter ≤2 cm were evaluated by US and CEUS examinations. All nodules were examined by core-needle biopsy or surgical pathology.The collected ultrasound images and videos were analyzed by blind method. Stepwise Logistic regression was used to analyze the odds ratio of malignant nodules in ultrasound images, and the risk prediction score model was constructed according to OR value. The BI-RADS category was readjusted, and the diagnostic efficiencies before and after adjustment were compared with the ROC curve. Results:Multivariate Logistic regression analysis showed that the odds ratios of breast malignant nodules were non-circumscribed margin ( OR=3.32, P=0.052), calcification in the mass ( OR=7.42, P=0.002), architectural distortion ( OR=38.58, P<0.001), ductal dilatation ( OR=0.01, P=0.010), suspicious or abnormal axillary lymph nodes ( OR=10.92, P=0.003), enlarged lesion scope ( OR=3.38, P=0.040), penetrating vessels ( OR=10.79, P=0.006), and non-circumscribed margin after enhancement( OR=6.24, P=0.003). When the cut-off value was 3.5, the area under ROC curve, sensitivity, specificity and accuracy were 0.951, 87.80%, 89.20% and 88.57%, respectively. After adjusting BI-RADS classification and taking the adjusted BI-RADS category 4a as the biopsy threshold, the biopsy rate decreased from 100% to 58.86%, the cancer detection rate increased from 46.86% to 75.73%, and the risk of missed diagnosis was 2.29%. The area under ROC curve before and after BI-RADS classification adjustment was 0.838 and 0.937, respectively. Conclusions:US combined with CEUS can improve the diagnostic efficiency of BI-RADS category 4 small breast nodules and reduce unnecessary biopsy.