总结非哺乳期乳腺炎中常见的浆细胞性乳腺炎（PCM）及肉芽肿性乳腺炎（GM）的超声和MRI表现特征。

回顾性分析2015年4月至2017年8月上海交通大学医学院附属瑞金医院收治的经手术或穿刺活检病理证实的75例非哺乳期乳腺炎患者，共75个病灶。所有患者术前均行超声、MRI检查。采用χ²检验比较不同类型非哺乳期乳腺炎超声、MRI表现特征。

本组75个病灶，17个为PCM，20个为GM，38个为其他类型乳腺炎，包括化脓性炎、小管炎及结核等。不同类型非哺乳期乳腺炎超声表现的形态、回声水平、血供程度、血供模式及向脂肪组织蔓延差异均有统计学意义（χ²=7.747，P=0.021；χ²=10.923，P=0.027；χ²=29.609，P<0.001；χ²=10.806，P=0.029；χ²=7.939，P=0.019）。其中PCM病灶血供多丰富，且以边缘型为主，同时更易向脂肪组织蔓延；GM病灶血供则以混合型为主。不同类型非哺乳期乳腺炎病灶位置及其边缘光整差异，以及超声探及的腋窝淋巴结显示差异均无统计学意义。不同类型非哺乳期乳腺炎MRI表现的腺体致密、强化方式、时间-信号强度曲线类型、腋窝淋巴结显示差异均有统计学意义（χ²=6.724，P=0.035；χ²=15.576，P=0.016；χ²=12.457，P=0.014；χ²=6.394，P=0.041）。PCM病灶多为肿块样强化；GM则以非肿块样强化及环形强化者较多，强化后腋窝淋巴结显示者较多。不同类型非哺乳期乳腺炎病灶平扫信号、位置、形态、边缘差异均无统计学意义。本组75个病灶，超声诊断准确率为52.0%（39/75），误诊率为48.0%（36/75）；MRI诊断准确率为26.7%（20/75），误诊率为73.3%（55/75）；超声联合MRI诊断准确率为57.3%（43/75），误诊率为42.7%（32/75）。

不同类型非哺乳期乳腺炎的影像学表现不尽相同，不同检查方法联合有助于诊断。

To summarize the ultrasound and magnetic resonance imaging (MRI) features of plasma cell mastitis (PCM) and granulomatous mastitis (GM), the two most common forms of non-lactating mastitis.

From April 2015 to August 2017, a total 75 lesions from 75 patients with mastitis were retrospectively analyzed. All of these lesions were pathologically confirmed by surgery or biopsy at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine. All of these patients had undergone ultrasound and MRI before the surgery or biopsy. Ultrasound and MRI features of different types of non-lactating mastitis were compared by the χ² test.

Of the total 75 lesions evaluated in this study, 17 were PCM, 20 were GM, and the remaining 38 were other types of mastitis, such as suppurative inflammation, tubulitis, and tuberculosis. The shape, echo pattern, vascular pattern and extent of the blood supply, and spread to the fat of breast lesions in ultrasound had significant differences between different types of non-lactating mastitis (χ²=7.747, P=0.021; χ²=10.923, P=0.027; χ²=29.609, P<0.001; χ²=10.806, P=0.029; χ²=7.939, P=0.019). PCM always had more blood supply than other types and more likely spread to the fat, with marginal type being the main blood supply pattern. For GM, the blood supply patter were mainly the mixed type. There were also some ultrasound features with no statistical difference, such as the location of the lesion, whether the margin was smooth or not, as well as the detection of axillary lymph nodes in ultrasound. The gland density level, enhancement pattern, time-signal intensity curve type, and detection of abnormal lymph nodes in MRI were statistically different among different types of mastitis (χ²=6.724, P=0.035; χ²=15.576, P=0.016; χ²=12.457, P=0.014; χ²=6.394, P=0.041). Most of the PCM lesions were enhanced like tumors, and the GM lesions were mostly ring enhanced unlike tumors, with more axillary lymph nodes detected after enhancement. There were no statistically significant differences in the location of the lesion, shape, margin difference, or detection by non-enhanced scan. The diagnostic accuracy of ultrasound was 52.0% (39/75), and the rate of misdiagnosis was 48.0% (36/75). The diagnostic accuracy of MRI was 26.7% (20/75), and the rate of misdiagnosis was 73.3% (55/75). The diagnostic accuracy of ultrasound combined with MRI was 57.3% (43/75), and the rate of misdiagnosis was 42.7% (32/75).

The imaging features of mastitis have unique characteristics, and the combination of ultrasound and MRI is helpful in diagnosing mastitis.