目的：探讨超声乳腺影像报告和数据系统（BI-RADS）在微小乳腺癌诊断中的临床价值。方法：回顾性分析超声诊断为BI-RADS 3~5级的255例微小乳腺病灶的超声征象描述、分级结果与病理结果。结果：255例病灶经病理证实良性191例，恶性64例。超声BI-RADS诊断微小乳腺癌的灵敏性、特异性、准确性、阳性预测值（PPV）、阴性预测值（NPV）分别为89.06%、80.63%、82.75%、60.64%、95.65%。边缘不光整、形态不规则、纵横比≥1、内部有微钙化、内部血流阻力指数（RI）≥0.7、后方回声衰减、周围组织改变等7个超声征象在良恶性病灶中的差异具有统计学意义（P<0.05），其中灵敏性较高的有边缘不光整（82.81%）、形态不规则（85.94%），特异性较高的有纵横比≥1（89.53%）、内部有微钙化（90.05%）、内部血流RI≥0.7（92.67%）、后方回声衰减（95.29%）、周围组织改变（99.48%）。结论：超声BI-RADS能较准确的评估微小乳腺病灶的良恶性，有助于微小乳腺癌的的早期发现、早期诊断和早期治疗。

Objective: To investigate the clinical value of ultrasound breast imaging reporting and data system(BI-RADS) in diagnosis of breast small carcinoma. Methods: We retrospectively analyzed ultrasound features, BI-RADS classification and pathological results of 255 small breast lesions which were diagnosed as 3~5 staged ultrasound BI-RADS. Results: The pathological results suggested that among 255 small breast lesions there are 191 benign lesions and 64 malignant lesions. The sensitivity, specificity, accuracy, positive predictive value(PPV) and negative predictive value(NPV) of ultrasound BI-RADS classification were 89.06%, 80.63%, 82.75%, 60.64% and 95.65%, respectively. The differences in non-circumscribed margin, irregular shape, aspect ratio>1, microcalcification in mass, lesions internal resistance index(RI)≥0.7, shadowing and the changes of surrounding tissue between benign and malignant lesions were statistically significant(P<0.05). Higher sensitivity was found in non-circumscribed margin(82.81%) and irregular shape(85.94%). Higher specificity was found in aspect ratio>1(89.53%), microcalcification in mass(90.05%), lesions internal RI≥0.7(92.67%), shadowing(95.29%) and the changes of surrounding tissue(99.48%). Conclusion: Ultrasound BI-RADS is of great value in diagnosing the benign and malignant breast masses and contributed to early detection, diagnosis, treatment of breast tiny carcinoma.