CEUS Helps to Rerate Small Breast Tumors of BI-RADS Category 3 and Category 4

Purpose. The primary aim of this study was to explore if classification, whether using the BI-RADS categories based on CEUS or conventional ultrasound, was conducive to the identification of benign and malignant category 3 or 4 small breast lesions. Material and Methods. We evaluated 30 malignant and 77 benign small breast lesions using CEUS. The range of enhancement, type of enhancement strength, intensity of enhancement, and enhancement patterns were independent factors included to assess the BI-RADS categories. Results. Of the nonenhanced breast lesions, 97.8% (44/45) were malignant, while, of the hyperplasic nodules, 96.8% (30/31) showed no enhancement in our study. Category changes of the lesions were made according to the features determined using CEUS. The results showed that these features could improve diagnostic sensitivity (from 70.0 to 80.0, 80.0, 90.0, and 90.0%), reduce the negative likelihood ratio (from 0.33 to 0.22, 0.25, 0.11, and 0.12), and improve the NPV (from 88.8 to 92.2, 91.2, 96.2, and 95.5%). However, this was not conducive to improve diagnostic specificity or the PPV. Conclusion. The vast majority of nonenhanced small breast lesions were malignant and most of the hyperplasic nodules showed no contrast enhancement. As a reference, CEUS was helpful in identifying BI-RADS category 3 or 4 small breast lesions.