ADC最小值、rADC最小值与肾透明细胞癌Fuhrman分级的相关性分析

Correlation analysis between ADC minimum,rADC minimum and Fuhrman classification of renal clear cell carcinoma

目的探讨3.0 T MR表观扩散系数最小值(apparent diffusion coefficient minimum,ADCmin)、相对ADC最小值(relative apparent diffusion coefficient minimum,rADCmin)在预测肾透明细胞癌(clear cell renal cell carcinoma,CCRCC)病理分级中的应用价值,并与ADC平均值(mean apparent diffusion coefficient,ADCmean)作比较。材料与方法回顾性分析经手术病理确诊的92例肾透明细胞癌患者的病理及MRI扩散加权成像(diffusion weighted imaging,DWI)检查资料,测量病灶实质的ADCmean、ADCmin及对侧肾实质的ADC值,并计算rADCmin。依据Fuhrman核分级法,分为低级别组(Ⅰ、Ⅱ级)和高级别组(Ⅲ、Ⅳ级);比较Ⅰ~Ⅳ级间及高、低级别组间ADCmean、ADCmin、及rADCmin的差异;分析病灶ADC值与Fuhrman分级之间的相关性;并绘制受试者工作特征(receiver operating characteristic,ROC)曲线,评价三种ADC值对高、低级别CCRCC的诊断效能。结果四个病理分级之间ADCmean、ADCmin及rADCmin差异均有统计学意义(P<0.05);高、低级别组ADCmean分别为(1.578±0.188)×10^-3 mm^2/s,(1.956±0.206)×10^-3 mm^2/s,ADCmin分别为(1.291±0.134)×10^-3 mm^2/s,(1.682±0.223)×10^-3 mm^2/s,rADCmin为0.591±0.065,0.777±0.093,差异有统计学意义(P<0.01);ADCmean、ADCmin、及rADCmin与Fuhrman分级之间均呈高度负相关(r=-0.755、r=-0.826、r=-0.880,P<0.01);在鉴别高、低级别CCRCC方面,rADCmin诊断效能最高,ROC曲线下面积(area under the curve,AUC)为0.963,以0.6673为界值,敏感度为91.2%,特异度为88.6%。结论ADCmin在预测肾透明细胞癌Fuhrman病理分级及诊断效能方面优于ADCmean,而rADCmin评估价值最高,可为临床制定手术方案及评估预后提供参考。

Objective:To investigate the application value of 3.0 T MRI minimum apparent diffusion coefficient(ADCmin)and relative ADC minimum(rADCmin)in predicting the pathological grades of renal clear cell carcinoma(CCRCC),and compare them with mean apparent diffusion coefficient(ADCmean).Materials and Methods:Retrospective analysis of pathological and DWI data of 92 patients with renal clear cell carcinoma confirmed by surgical pathology.The average and minimum ADC values of the parenchyma of the lesion,and the ADC value of contralateral renal parenchyma were measured,and then the rADCmin was calculated.According to Fuhrman nuclear grading system,GradeⅠandⅡwere defined as low-grade group,and gradeⅢandⅣwere defined as high-grade group.The values of ADCmean,ADCmin,and rADCmin were compared amongⅠ—Ⅳpathological grades,and between high-grade group and low-grade group.The correlation between Fuhrman classification and ADC values was analyzed.ROC curve was performed to evaluate the diagnostic efficacy of three different ADC values for high and low grade CCRCC.Results:There were statistically significant differences in ADCmean,ADCmin and rADCmin among the four pathological grades(P<0.05).The ADCmean of the high and low grade groups were(1.578±0.188)×10^-3 mm^2/s,(1.956±0.206)×10^-3 mm^2/s,and the ADCmin were(1.291±0.134)×10^-3 mm^2/s,(1.682±0.223)×10^-3 mm^2/s,rADCmin were 0.591±0.065,0.777±0.093(P<0.01).There was a highly negatively correlated between pathological grades and ADCmean,ADCmin,and rADCmin(r=-0.755,r=-0.826,r=-0.880 respectively,P<0.01);rADCmin had the highest diagnostic effectiveness in identifying high and low grade CCRCC,and the area under ROC was 0.963.With 0.6673 as the best diagnostic threshold,the sensitivity was 91.2%and the specificity was 88.6%.Conclusions:ADCmin is superior to ADCmean in predicting the Fuhrman pathological grades and diagnostic efficacy of renal clear cell carcinoma,and rADCmin has the highest evaluation value,which can provide reference for clinical operation and prognostic evaluation.