多b值DWI联合DCE-MRI定量参数在小肾癌诊断中的应用

Application of multi-b value DWI combined with DCE-MRI quantitative parameters in diagnosis of small renal cell carcinoma

目的探讨多b值扩散加权成像(DWI)联合动态对比增强磁共振成像(DCE-MRI)定量参数诊断小肾癌(sRCC)的应用价值。方法选取sRCC患者120例(sRCC组)、肾脏良性病变患者101例(良性病变组)为研究对象,入院时均接受多b值DWI、DCE-MRI及联合检查,均经手术病理检查确诊;比较2组患者多b值DWI参数[表观扩散系数(ADC)]、DCE-MRI定量参数[容量转移常数(Ktrans)、速率常数(Kep)];分析各参数用于sRCC的诊断价值。结果b=400 s/mm^(2)、1000 s/mm^(2)时,2组ADC值比较差异无统计学意义(P>0.05);b=800 s/mm^(2)时,sRCC组患者ADC值低于良性病变组,差异有统计学意义(P<0.05);2组Kep值比较差异无统计学意义(P>0.05);sRCC组患者Ktrans值高于良性病变组,差异有统计学意义(P<0.05);绘制ROC曲线显示,以Ktrans为0.335/min、b=800 s/mm^(2)条件下的ADC值为1.575×10^(-3)mm^(2)/s作为sRCC、良性病变的诊断阈值,差异有统计学意义(P<0.05),即Ktrans>0.335 min-1、ADC值<1.575×10^(-3)mm^(2)/s判定为sRCC,此时二者诊断AUC分别为0.884、0.900;根据ADC、Ktrans阈值判断sRCC结果显示,ADC与Ktrans阈值联合诊断sRCC的检出率高于二者单独诊断,差异有统计学意义(P<0.05);ADC与Ktrans阈值检查sRCC与病理结果具有理想一致性,Kappa值分别为0.733、0.741,均低于二者联合检查的0.881。结论在b为800 s/mm^(2)条件下,DWI定量分析ADC值联合DCE-MRI定量参数Ktrans阈值用于诊断sRCC有一定价值,应用前景好。

Objective To investigate the application value of multi-b value diffusion weighted imaging(DWI)combined with dynamic contrast enhanced magnetic resonance imaging(DCE-MRI)quantitative parameters in diagnosis of small renal cell carcinoma(sRCC).Methods A total of 120 patients with sRCC were enrolled as sRCC group,and the other 101 patients with benign renal diseases were enrolled as benign lesion group.The patients in both groups underwent multi-b value DWI,DCE-MRI and combined examination on admission,who were diagnosed by surgical pathological examination.The multiple b-value DWI parameters[apparent diffusion coefficient(ADC)]and DCE-MRI quantitative parameters[volume transfer constant(Ktrans),rate constant(Kep)]were observed and compared between the two groups to analyze the diagnostic value of each parameter.Results When b=400s/mm^(2),1,000s/mm^(2),there was no significant difference in the ADC value between the two groups(P>0.05);when b=800s/mm^(2),the ADC value in sRCC group was significantly lower than that in benign disease group(P<0.05);there was no significant difference in the Kep value between the two groups(P>0.05).The Ktrans value in sRCC group was significantly higher than that in benign disease group(P<0.05).The ROC curve showed that the ADC value of 1.575×10^(-3)mm^(2)/s under the condition of Ktrans of 0.335/min and b=800s/mm^(2) was taken as the diagnostic threshold of sRCC and benign lesions,the diagnosis AUC was 0.884 and 0.900,respectively.The detection rate of sRCC by combination detection of ADC and Ktrans threshold was significantly higher than that by single index detection(P<0.05).Moreover the results of combination detection of ADC and Ktrans threshold in diagnosis of sRCC were closely consistent with pathological examination results,and the Kappa values were 0.733 and 0.741,respectively,which was significantly lower than that(0.881)by single index detection(P<0.05).Conclusion Under the condition of b=800s/mm^(2),DWI quantitative analysis of ADC value combined with DCE-MRI quantitative parameter Ktrans threshold has certain value in diagnosing sRCC,with better application prospect.