MRI表观扩散系数联合动态增强TIC类型对肿块型浆细胞性乳腺炎及乳腺癌的鉴别诊断价值

The differential diagnosis value of MRI apparent diffusion coefficient value combined with dynamic contrast enhanced MRI time-intensity curve type for mass plasma cell mastitis and breast cancer

目的探讨MRI表观扩散系数(apparent diffusion coefficient,ADC)及相对表观扩散系数(relative apparent diffusion coefficient,rADC)联合动态增强时间-信号强度曲线(time-intensity curve,TIC)类型对肿块型浆细胞性乳腺炎(plasma cell mastitis,PCM)及乳腺癌的鉴别诊断价值。材料与方法回顾性分析经病理证实的21例肿块型PCM及31例乳腺癌患者的MRI资料,测量病灶、同侧胸大肌及对侧正常乳腺腺体的平均ADC值,并计算其rADC值,即rADC1=病灶平均ADC值/同侧胸大肌平均ADC值;rADC2=病灶平均ADC值/对侧正常乳腺腺体平均ADC值;根据动态增强MRI (dynamic contrastenhanced MRI,DCE-MRI)数据绘制病灶的TIC。采用χ^2检验或Fisher确切概率法比较肿块型PCM及乳腺癌的各项MRI表现及TIC类型;采用独立样本t检验比较平均ADC值、rADC值;以病理结果为金标准,绘制ADC、rADC值的非参数法受试者工作特征曲线(receiver operating characteristic curve,ROC);对ADC、rADC值与TIC类型进行logistic回归分析,计算联合因子后,对各联合因子绘制ROC,探讨ADC、rADC联合TIC类型对肿块型PCM及乳腺癌的鉴别诊断价值。结果肿块型PCM病灶多位于乳晕后区,形态多呈不规则形,边缘多无毛刺,常伴有导管扩张,增强扫描常呈明显强化,TIC多为Ⅰ型或Ⅱ型(90.5%)。肿块型PCM的平均ADC值、平均rADC1、rADC2值分别为(1.17±0.09)×10^-3mm^2/s、0.79±0.08、0.61±0.10,均高于乳腺癌组,且组间差异均具有统计学意义(P<0.05)。平均ADC值的诊断阈值为1.47×10^-3mm^2/s,曲线下面积(areaunder the curve,AUC)为0.897,灵敏度为95.2%,特异度为77.4%,rADC值诊断的灵敏度低于ADC值,但特异度较高;联合TIC类型后,ADC、rADC值的诊断效率、灵敏度均增加,除rADC1外,特异度均增加。结论 MRI平均ADC值、rADC值对浆细胞性乳腺炎及乳腺癌具有鉴别诊断价值,联合动态增强TIC类型后,可提高诊断效率。

Objective:To investigate the differential diagnosis value of MRI apparent diffusion coefficient (ADC) and relative apparent diffusion coefficient (rADC) combined with dynamic contrast enhanced MRI (DCE-MRI) time-intensity curve (TIC) for mass plasma cell mastitis (PCM) and breast cancer.Materials and Methods:MRI data of 21 cases of mass PCM and 31 cases of breast cancer confirmed by pathology were retrospectively analyzed.The mean ADC values of lesions,ipsilateral ectopectoralis and contralateral breast glands were measured,then calculate the mean relative apparent diffusion coefficient (rADC) values.TIC was drafted according to DCE-MRI data.MRI findings and TIC types of mass PCM and breast cancer were compared by χ^2 test or Fisher exact probability test.The mean ADC and rADC values were compared by independent sample t test.P<0.05 was considered statistically significant.Based on the pathological results,the non-parametric receiver operating characteristic curve (ROC) of ADC and rADC values was drawn.A logistic regression analysis was conducted to calculate the combination factors of ADC,rADC values combined with TIC types,then ROC of the factors was drafted to figure out the differential diagnosis value of combination test for mass PCM and breast cancer.Results:Mass PCM lesions were mostly located in the posterior area of areola with an irregular shape and rough margins,and often accompanied by duct dilatation.In DCE-MRI,PCM lesions generally showed significant enhancement,and the TIC types were generally Ⅰ or Ⅱ(90.5%).The mean ADC,rADC1,and rADC2 values of PCM were (1.17±0.09)×10^-3mm^2/s,0.79±0.08 and 0.61±0.10,these values were higher than those of breast cancer,and the difference were statistically significant (P<0.05).The diagnostic threshold of mean ADC value was 1.47×10^-3mm^2/s,the area under the curve (AUC) was 0.897,the sensitivity was 95.2%,and the specificity was 77.4%.The specificity of the mean rADC value is higher than the mean ADC value.When combined with TIC type,the diagnostic efficiency and sensitivity of ADC and rADC values increased,and the specificity increased except for rADC1.Conclusions:The mean ADC,rADC values have differential diagnostic value for mass PCM and breast cancer,the diagnostic efficiency is increased when DCE-MRI TIC types were combined.