IVIM定量参数在肾肿瘤诊断中的初步应用

Preliminary Application of IVIM Quantitative Parameters in the Diagnosis of Renal Tumors

目的探讨体素内不相干运动(IVIM)的定量参数在肾透明细胞癌(ccRCC)与血管平滑肌脂肪瘤(AML)诊断中的应用价值。方法搜集经病理证实的38例肾肿瘤患者,其中ccRCC 23例,包括低级别(Ⅰ~Ⅱ级)18例,高级别(Ⅲ~Ⅳ级)5例;AML 15例。所有患者行常规腹部磁共振检查及IVIM扫描。运用后处理软件生成IVIM参数图。在连续三个病灶较大的层面、瘤旁肾实质及对侧正常肾实质设置感兴趣区(ROI),分别测量真实扩散系数(slow-ADC)、假性扩散系数(fast-ADC)和灌注分数(f)参数,取其平均值。比较IVIM参数在ccRCC与AML、以及高级别和低级别ccRCC之间的差异,并分析参数最佳诊断界值。采用单因素方差分析比较ccRCC组内肿瘤病灶、瘤旁肾实质及对侧正常肾实质的各参数差异。结果 slow-ADC及f值在ccRCC与AML之间的差异具有统计学意义(P﹤0.05);其对应的最佳诊断界值分别为0.985×10^(-3)mm^(2)/s、0.32,敏感度、特异度和曲线下面积(AUC)分别为69.6%、87.5%和0.799;91.3%、62.5%和0.796。fast-ADC在组间比较差异无统计学意义(P=0.885)。slow-ADC、fast-ADC及f值在ccRCC低级别与高级别之间的差异具有统计学意义(P﹤0.05),其对应的最佳诊断界值分别为0.74×10^(-3)mm^(2)/s、0.03 mm^(2)/s、0.5,敏感度、特异度和AUC分别为94.4%、100%和0.956;72.2%、100%和0.822;61.1%、100%和0.8。ccRCC肿瘤、瘤旁肾实质及对侧正常肾实质三者之间的slow-ADC与f值差异均有统计学意义(P﹤0.05),但fast-ADC值差异无统计学意义。结论 slow-ADC及f值可用于ccRCC与AML的鉴别诊断,也可用于分析ccRCC对瘤旁肾实质的影响。

Objective To explore the application of quantitative parameters of intravoxel incoherent motion(IVIM) in the diagnosis of clear cell renal cell carcinoma and angiomyolipoma. Methods A total of 38 lesions diagnosed were included in the study analysis including 15 cases of angiomyolipoma and 23 cases of clear cell renal cell carcinoma which were divided into 18 cases of low level(grade Ⅰ~Ⅱ) and 5 cases of high level(grade Ⅲ~Ⅳ).All patients underwent conventional abdominal magnetic resonance examination and IVIM scan.The post-processing software MADC was used to generate the IVIM parameter map.ROI was set in the lesion location, para-tumor renal parenchyma and contralateral normal renal parenchyma at larger three consecutive layers, and each parameter(including slow-ADC,fast-ADC and f values) was measured respectively, and the mean value was taken.IVIM parameters were compared between angiomyolipoma and clear cell renal cell carcinoma, the high and low grades of clear cell renal cell carcinoma.ANOVA was used to compare the parameters of tumor lesion, para-tumor renal parenchyma and contralateral normal renal parenchyma in the clear cell renal cell carcinoma. Results The differences of slow-ADC and f values between clear cell renal cell carcinoma group and angiomyolipoma group were statistically significant(P< 0.05).The thresholds of slow-ADC and f values were 0.985×10^(-3)mm^(2)/s、0.32,in which the corresponding sensitivity, specificity, and AUC were 69.6%,87.5% and 0.799;91.3%,62.5% and 0.796.There is no statistically significant difference in fast-ADC(P=0.885).The differences of slow-ADC,fast-ADC and f values between high and low level of clear cell renal cell carcinoma were statistically significant(P< 0.05).The thresholds of slow-ADC,fast-ADC and f values were 0.74×10^(-3)mm^(2)/s, 0.03 mm^(2)/s and 0.5,in which the corresponding sensitivity, specificity, and AUC were 94.4%,100% and 0.956;72.2%,100% and 0.822;61.1%,100% and 0.8.There were statistically significant differences of slow-ADC and f values in the tumor lesion, para-tumor renal parenchyma and contralateral normal renal parenchyma in the clear cell renal cell carcinoma group(P<0.05),but the difference of fast-ADC value is not statistically significant(P> 0.05). Conclusion slow-ADC and f values are of high value in the diagnosis of clear cell renal cell carcinoma and angiomyolipoma.It is valuable to observe the effect of renal malignancy on renal parenchyma.