中文摘要：

目的评价超声弹性应变率比值与MRI及其联合应用对乳腺肿物的诊断价值。资料与方法收集经手术病理证实为乳腺良恶性肿物的54例患者,均行弹性超声及MRI检查,通过定量超声弹性成像技术测定肿物与周围正常乳腺组织的应变率比值（SRR）,绘制受试者操作特征（ROC）曲线获得区分乳腺肿物良恶性的最佳临界值,比较超声SRR、MRI及两者联合应用诊断乳腺肿物的准确度。结果良性组SRR为2.24±1.28,与恶性组的4.96±1.73比较,差异有统计学意义（t=2.648,P〈0.05）。通过ROC曲线确定超声SRR诊断乳腺肿物良恶性的最佳临界值为2.41。超声SRR、MRI、SRR联合MRI应用诊断乳腺良恶性肿物的准确度分别为81.48%（44/54）、85.19%（46/54）、96.30%（52/54）;超声SRR与MRI诊断准确度比较,差异无统计学意义（χ^2=0.267,P〉0.05）;联合诊断准确度明显高于超声SRR、MRI的诊断准确度（χ^2=6.000、3.967,P〈0.05）。结论超声SRR对乳腺肿瘤良恶性的诊断准确性较高,可为临床鉴别诊断乳腺实性病灶良恶性提供更有价值的量化指标,同时结合MRI诊断可减少误诊和漏诊。

英文摘要：

Purpose To evaluate the significance of ultrasonic elastography strain ratio, MRI and the combination of both in diagnosis of breast tumor. Materials and Methods Fifty-four cases with single breast tumor underwent preoperative ultrasound elasticity imaging and MRI. Accuracy of ultrasound elastography strain rate ratio（SRR） of the tumor and surrounding normal breast tissue was measured by quantitative ultrasound elastography, and its combination with MRI were analyzed. Results There was significant differences on SRR between the benign group and the malignant group（2.24±1.28 vs 4.96±1.73, t=2.648, P〈0.05）. Optimal threshold of ultrasonic elastography SRR in differential diagnosis of breast benign from malignant tumor was 2.41 determined by ROC curve. The accuracy of SRR, MRI and the combination of both in differentiating benign from malignant breast tumor was 81.48%（44/54）, 85.19%（46/54） and 96.30%（52/54）, respectively. There was no statistic difference between SRR and MRI in diagnostic accuracy（χ~2=0.267, P〉0.05）. Combined both had higher diagnosis accuracy when compared with SR and MRI separately（χ~2=6.000 and 3.967, P〈0.05）. Conclusion Ultrasonic elastography strain ratio is accurate and objective in differentiating benign from malignant breast tumors. It is a valuable quantitative index in clinical practice. Moreover, SRR combined with MRI can reduce the misdiagnosis rate.