目的　评价MRI诊断乳腺恶性肿瘤的临床应用价值。方法　对 3 7例乳腺恶性肿瘤进行MRI平扫和增强扫描 ,并对照X线、B超及手术病理结果 ,分析比较了增强前病变形状、边界、内部信号 ,以及增强后病变强化特征。结果　平扫及增强MRI对3 7例乳腺恶性肿瘤患者的诊断准确率分别为 84.5 %和 94.6%。结论　平扫及增强MRI是诊断乳腺恶性肿瘤的有效影像学方法。 Objective To evaluate the clinical application value of MRI in the diagnosis of malignant breast tumors. Methods MRI scans and enhanced scans were performed on 37 cases of breast malignant tumors. The X-ray, B-ultrasound, and surgical pathology results were compared. The shapes, boundaries, internal signals of enhanced pre-lesions, and enhancement features of enhanced lesions were analyzed and compared. Results The accuracy of plain scan and contrast-enhanced MRI in diagnosis of 33 patients with breast cancer was 84.5% and 94.6%, respectively. Conclusion Plain and enhanced MRI are effective imaging methods for diagnosing breast cancer.