目的：探讨非特异性乳腺炎的MRI表现及与乳腺癌的鉴别诊断。方法：分析2013年1月—2016年3月病理证实的非特异性乳腺炎29例30个病灶的MRI表现，同时随机抽取相同时段经病理证实的乳腺癌患者20例作为对照组，比较2组间在MRI平扫、DWI、DCE、EER、时间-信号曲线（TIC）、MIP表现的异同。结果：30个炎性病变，13例病变区含有脂肪信号，全部病例于T2WI均见有高信号；28例病变环状强化或伴强化分隔，29例DWI呈高信号，ADC值平均（0.707±0.181）×10-3 mm2/s，其中53.3%的病例＜0.700×10-3 mm2/s；73.3%的TIC Ⅰ型；EER：平均123%±50%，＞80% 26例，≤80% 4例。MIP：21例血运增加。20例乳腺癌，2例于T2WI呈稍高信号，10例表现为向心性环状强化；DWI均呈高信号，ADC值平均（0.874±0.108）×10-3 mm2/s，2例＜0.700×10-3 mm2/s，85%的TIC为Ⅱ~Ⅲ型；EER：平均137%±36%，＞80% 19例，≤80% 1例；MIP：16例血运增加。以≤0.700×10-3 mm2/s为炎性病变， ADC值对炎性病变的敏感性88.89%， 特异性56.25%， 准确性68%， 二者之间的差异有统计学意义（χ2=6.74，P＜0.01）。TIC以Ⅰ型为良性病变，Ⅱ、Ⅲ型为恶性病变，TIC在二者之间有统计学意义（χ2=16.33，P＜0.01）；EER及MIP在二者之间没有统计学意义（χ2=0.23（校正），P＞0.05；χ2=0.62，P＞0.05）。结论：非特异性乳腺炎MRI表现具有一定特征性，MRI平扫结合动态增强扫描形态学及血流动力学参数对乳腺癌的鉴别诊断有重要价值。

Objective: To investigate the MRI features of nonspecific mastitis and differential diagnosis between nonspecific mastitis and breast cancer. Methods: The MRI findings of 30 lesions of 29 cases with nonspecific mastitis confirmed by pathology from January 2013 to March 2016 were analyzed, and 20 breast cancer patients confirmed by pathology in the same period were randomly selected as control group, and the difference of MRI, DWI, DCE, EER, TIC and MIP findings between the two groups were compared. Result: In 30 lesions, 13 cases showed fat signal, all lesions showed high signal intensity on T2WI; 28 cases had ring reinforcement and enhanced separation, 29 cases showed high signal intensity on DWI, the mean value of ADC was (0.707±0.181)×10-3 mm2/s, and 53.3% of the cases were less than 0.700×10-3 mm2/s; 73.3% cases TIC was type Ⅰ. The mean value of EER was 123%±50%, 26 cases>80%, 4 cases≤80%. MIP: blood supply in 21 cases were increased. In 20 cases with breast cancer, 2 cases showed slightly high signal intensity on T2WI, 10 cases had centripetal and ring reinforced; all cases showed high signal intensity on DWI, the mean value of ADC was (0.874±0.108)×10-3 mm2/s, 2 cases<0.700×10-3 mm2/s, 85% cases TIC type Ⅱ~Ⅲ. The mean value of EER was 137%±36%, 19 cases>80%, 1 case≤80%; MIP: blood supply in 16 cases were increased, with ≤0.700×10-3 mm2/s for inflammatory lesions. The sensitivity, specificity and accuracy of ADC values respectively were 88.89%, 56.25% and 68% in inflammatory lesions, the differences were statistically significant between the two groups（χ2=6.74, P＜0.01）. TIC type Ⅰ was benign lesions while type Ⅱ and Ⅲ were malignant lesions. There were significant differences in TIC between the two groups(χ2=16.33, P＜0.01). There was no significant difference in EER and MIP between the two groups(χ2=0.23(correction), P＞0.05; χ2=0.62, P＞0.05). Conclusion: MRI findings of nonspecific mastitis have certain characteristics. MRI plain scan combined with dynamic enhanced scan, morphology and hemodynamic parameters have important value in the differential diagnosis of breast cancer.