兔VX2乳腺癌T2*首过MR灌注成像与肿瘤微血管密度的相关性研究

目的应用MR灌注成像动态观察兔VX2移植型乳腺癌模型的成瘤过程,评价MR灌注成像(PWI)在反映乳腺癌的肿瘤血管生成方面的价值。方法建立20只新西兰大白兔乳腺VX2瘤模型,随机排列成A、B、C、D4组,分别于肿瘤种植后9、14、21、28天进行T2*WI的PWI,根据MRT2*首次通过灌注成像绘制时间-信号强度曲线图,对肿瘤最大信号强度下降率和最大信号强度下降时间作为参数用于肿瘤灌注的定量分析,观察其变化规律。取病理标本进行免疫组化CD31染色,计数微血管密度(MVD),将MR灌注参数与MVD进行相关性分析。结果B组VX2移植型乳腺癌的最大信号强度下降率明显高于A、C、D组(F=5.93,P<0.05)。结论MR灌注成像参数与MVD相关,可以从一个角度反映肿瘤的血管生成情况。

Correlation of MR T2* first-pass perfusion weighted imaging and microvessel density in rabbit breast with VX2 carcinoma

Objective To evaluate the dynamic characteristics of the VX2 transplanted carcinoma model in rabbit breast on MR perfusion weighted imaging(PWI),and to assess the value of PWI in detecting breast tumor angiogenesis.Methods Twenty New Zealand white rabbits with VX2 carcinoma were randomly arranged in 4 groups(each n=5).T2* first-pass PWI and microvessel density(MVD)counting were performed on 9,14,21,28 days after tumor implantation in group A,B,C and D,respectively.The signal intensity-time curves were made according to the T2* first-pass perfusion weighted imaging.The maximal signal intensity drop rate and maximal signal intensity decrease time were analyzed as quantitative variable for tumor PWI,respectively.Immunohistochemical CD31 staining was conducted on pathological sections.MVD was measured case by case.The correlation on PWI parameter with MVD was studied.Results The maximal signal intensity drop rate of rabbit VX2 transplanted breast carcinoma of B group was higher than that of A,C,D group(F=5.93,P<0.05).Conclusion MR perfusion imaging parameters associate with MVD,and may reflect the tumor angiogenesis in another aspect.