RESUMO
<p><b>OBJECTIVE</b>To assess the clinical value of contrast-enhanced ultrasonography (CEUS) in early diagnosis of breast cancer.</p><p><b>METHODS</b>CEUS was performed in 107 cases of ultrasound BI-RADS(®) category 3 or category 4 small breast tumors (diameter no greater than 10 mm) before surgery. The range, type and patter of enhancement of the tumor and the surrounding tissues were observed, and the time-intensity curve (TIC) was analyzed for TIC curve type, basic and peak intensity, enhancement intensity, rising slope, and enhancement intensity. The results were analyzed comparatively between benign and malignant tumors.</p><p><b>RESULTS</b>The peak intensity, enhancement intensity index and peak time in CEUS were statistically significant between benign and malignant breast tumor (t=-2.310, -2.592, -2.127, P=0.021, 0.010, 0.033), and the intensity difference and rising slope also differed significantly (t=-3.422, -3.388, P=0.001, 0.001). TIC curve type, enhancement pattern, enhancement types and enhancement range were statistically significantly between benign and malignant breast tumor (P<0.001).</p><p><b>CONCLUSION</b>Benign and malignant BI-RADS(®) category 3 or 4 small breast tumors differ in the peak intensity, enhancement intensity index and peak time in CEUS. More nodular hyperplasia showed no enhancement in CEUS, and 97.8% of the lesions without enhancement are benign. In enhanced breast nodules, malignant breast lesions show more quick wash-in and wash-out type and quick wash-in and slow wash-out type, and the latter is more common; benign lesions often show a slow wash-in and slow wash-out type. In CEUS, the range of enhancement in malignant nodules is wider than that in two-dimensional ultrasound.</p>