目的 研究动态增强磁共振成像(dynamic contrast-enhanced MRI, DCE-MRI)定量参数对非肿块型乳腺癌的诊断价值.方法 回顾分析57例非肿块型乳腺癌患者MRI增强资料,所有患者行T1-DCE-MRI扫描,测量如下参数:容量转移常数(volume transfer constant, Ktrans)、速率常数(rate constant, Kep)、血管外细胞外间隙容积比(extravascular extracellular volume fraction, Ve) .参照乳腺MRI BI-RADS标准,分析病灶强化形态分布,采用独立样本t检验进行比较,并绘制ROC曲线.结果 非肿块型乳腺癌组与正常乳腺腺体组的Ktrans、Kep、Ve均值差异均有统计学意义(P值均<0.05);非肿块型乳腺癌依据强化形态分区段(伴线状强化)、区域与多区域性、局灶性及弥漫性强化四组,正常腺体组与四组间Ktrans、Kep均值差异均有统计学意义(P值均<0.05);正常腺体组与区段(伴线状强化)、区域与多区域组间Ve均值差异有统计学意义(P值均<0.05);正常腺体组与局灶及弥漫强化组间Ve差异无统计学意义(P值均>0.05).非肿块样强化四组组间Ktrans、Kep、Ve值差异无统计学意义(P值均>0.05).Ktrans、Kep、Ve三者ROC曲线下面积分别为0.996、0.920、0.821,以最大约登指数为最佳诊断切点值,则三者判断非肿块型乳腺癌的敏感性分别为92.2%、98.0%、98.0%;特异性分别为99.1%、62.0%、63.8%.结论 定量动态增强参数Ktrans、Kep值对诊断非肿块型乳腺癌有一定参考价值.
Objective To investigate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters in the diagnosis of non-mass breast cancer.Methods Analysis of 57 patients of non-mass breast cancer was performed AU.All underwent the DCE-MRI sequence.The following quantitative parameters were calculated: volume transfer constant (Ktrans), rate constant (Kep) and extravascular extracellular volume fraction (Ve).Referring to breast MRI BI-RADS, we analyzed the distribution of lesions form (linear, segmental, focal, regional, multi-regional, diffuse).The Ktrans, Kep and ve among non-mass breast cancer and normal glandular tissues, and all kinds enhancement form of non-mass breast carcinoma were calculated and compared by independent-sample T test, the areas under the ROC curve of Ktrans, Kep and Ve of non-mass breast cancer were analyzed.Results The difference of Ktrans, Kep and ve between malignant and normal glandular tissue was statistically significant (P<0.05).Non-mass breast cancer was divided into segmental (including liner), regional/multi-regional, focal and diffuse groups based on enhancement form.The difference of Ktrans, Kep between the four groups lesions and normal glandular tissue was statistically significant (P<0.05).The difference of Ve between normal glandular tissue and segmental(including liner) group, regional/multi-regional group was statistically significant (P<0.05).The difference of Ve between normal glandular tissue and focal group, diffuse group was not statistically significant (P>0.05).The mean Ktrans, Kep and Ve of the four groups was not statistically significant (P>0.05).The area under the ROC curve of Ktrans, Kep and Ve were 0.996, 0.920 and 0.821 respertively.The sensitivity of Ktrans, Kep and Ve were 92.2%, 98.0% and 98.0% respecti vely.The specificity were 99.1%, 62.0%, 63.8% respectively using the maximum Youden' index as the cut-off value.Conclusion Quantitative DCE-MRI parameters of Ktrans, Kep in the diagnosis of non-mass breast cancer have a certain reference value.