MRI-IVIM定量参数对直肠癌分化程度的鉴别研究

Study on identification of rectal cancer differentiation by quantitative parameters of MRI-IVIM

目的探讨磁共振体素内不相干运动成像(MRI-IVIM)定量参数对直肠癌分化程度的鉴别作用。方法回顾性分析2020年2—12月本院收治的158例直肠癌患者的临床资料,以病理检查结果为金标准,将其分为未、低分化组和中、高分化组。患者均在术前行MRI-IVIM检查,测定MRI-IVIM单指数模型[表观扩散系数(ADC)]、双指数模型[真扩散系数(D)、假扩散系数(D*)、灌注分数(f)]和拉伸指数模型[分布扩散系数(DDC),水分子扩散异质性指数(α)]各定量参数,比较两组患者MRI-IVIM定量参数的差异;绘制受试者工作特征(ROC)曲线分析MRI-IVIM定量参数单独与联合鉴别直肠癌分化程度的效能。结果未、低分化组与中、高分化组患者性别、年龄比较差异均无统计学意义(P>0.05),未、低分化组TNM分期Ⅲ~Ⅳ期、有淋巴结转移、黏液癌及未分化癌患者高于中、高分化组(P<0.05);与中、高分化组相比,未、低分化组直肠癌患者ADC值、D值和DDC值降低(P<0.05),未、低分化组与中、高分化组直肠癌患者D*值、f值和α值差异无统计学意义(P>0.05);ADC值、D值和DDC值联合鉴别直肠癌分化程度的灵敏度均高于单独鉴别(P<0.01),AUC均高于单独鉴别(P<0.05),特异度均与单独鉴别差异无统计学意义(P>0.05)。结论未/低分化组直肠癌患者ADC值、D值和DDC值较中、高分化组降低,MRI-IVIM定量参数ADC值、D值和DDC值可鉴别直肠癌分化程度。

Objective To investigate the role of quantitative parameters of magnetic resonance intravoxel incoherent motion(MRI-IVIM)imaging in identifying the differentiation degree of rectal cancer.Methods The clinical data of 158 patients with rectal canceradmitted to our unit from February 2020 to December 2020 were retrospectively analyzed,and t divided into non/low differentiation group and medium/high differentiation group according to the pathological examination results as the gold standard.All patients were examined with MRI-IVIM before operation,and the quantitative parameters of MRI-IVIM single index model[apparent diffusion coefficient(ADC)],double index model[true diffusion coefficient(D),false diffusion coefficient(D*),perfusion fraction(f)]and tensile index model[distributed diffusion coefficient(DDC),water molecule diffusion heterogeneity index(α)]were determined.The quantitative parameters of MRI-IVIM were compared between the two groups.The ROC curve was drawn to analyze the efficacy of MRI-IVIM quantitative parameters in differentiating the differentiation degree of rectal cancer separately or in combination.Results There was no significant differences in gender,age between the non/low differentiation group and the medium/high differentiation group(P>0.05);the TNM stageⅢ~Ⅳ,lymph node metastasis,mucous carcinoma and undifferentiated carcinoma in non/low differentiation group were higher than those in medium/high differentiation group(P<0.05).Compared with the medium/high differentiation group,the ADC value,D value and DDC value of the patients with rectal cancer in the non/low differentiation group were significantly lower(P<0.05);however,there were no significant differences in D*value,f value andαvalue between non/low differentiation group and medium/high differentiation group(P>0.05).The combined sensitivity of ADC value,D value and DDC value to identify the differentiation degree of rectal cancer was higher than those of single differentiation(P<0.01),as well as the AUC(P<0.05),and the specificity was not significantly different from that of single identification(P>0.05).Conclusions ADC value,D value and DDC value in the non/low differentiation group of rectal cancer patients are lower than those in the medium/high differentiation group.ADC value,D value and DDC value as quantitative parameters of MRI-IVIM can distinguish the degree of rectal cancer differentiation.