磁共振ADC值和最大强化率在鉴别肝硬化背景下小肝癌与不典型增生结节中的应用

Application of magnetic resonance ADC value and maximum enhancement rate in differentiating small hepatocellular carcinoma and dysplastic nodule in the context of liver cirrhosis

目的:探讨磁共振(MR)弥散加权成像(DWI)的表观弥散系数(ADC)值和动态增强序列的病灶最大强化率(ERmax)在鉴别肝硬化背景下小肝癌(sHCC)和不典型增生结节(DN)中的应用价值。方法:回顾性分析2017年1月—2021年2月在我院行M R检查的49例肝硬化患者的临床和影像学资料,其中sHCC组24例,DN组25例。比较两组患者病灶ADC值和ERmax的差异。采用受试者工作特征(ROC)曲线分析ADC值和ERmax在两组间的鉴别诊断效能,并比较两者鉴别sHCC和DN的曲线下面积(AUC)差异。结果:sHCC组患者病灶ADC值显著低于DN组,ERmax则显著高于DN组(P<0.001)。病灶ADC值、ERmax鉴别sHCC和DN的最佳界值为1.40×10^(-3)mm^(2)/s和63.50%,敏感性分别为68.0%和96.0%,特异性分别为75.0%和87.5%,约登指数分别为0.430和0.835。病灶ERmax鉴别sHCC和DN的AUC显著大于ADC值的AUC(0.943 vs.0.796,P=0.026<0.05)。结论:磁共振ADC值和ERmax均可有效鉴别sHCC和DN,其中ERmax鉴别效能相对更高。

Objective To investigate the value of apparent diffusion coefficient(ADC)of magnetic resonance(MR)diffusion weighted imaging(DWI)and lesion maximum enhancement rate(ERmax)of dynamic enhancement sequence in differentiating small hepatocellular carcinoma(sHCC)and dysplastic nodule(DN)in the context of liver cirrhosis.Methods The clinical and imaging data of 49 patients with liver cirrhosis who underwent MR examination in our hospital were retrospectively analyzed,including 24 cases in the sHCC group and 25 cases in the DN group.The ADC value and ERmax of the lesions were compared between two groups.Receiver operating characteristic(ROC)curve was used to analyze the differential diagnostic efficacy of ADC value and ERmax between the two groups,and the difference of area under curve(AUC)between them for differentiating sHCC and DN was compared.Results The ADC value in sHCC group was significantly lower than that in DN group,while the ERmax was significantly higher than that in DN group(P﹤0.001).The optimal thresholds of ADC value and ERmax for the differentiation of sHCC and DN were 1.40×10^(-3)mm^(2)/s and 63.50%,the sensitivity was 68.0%and 96.0%,the specificity was 75.0%and 87.5%,and the Youden index was 0.430 and 0.835,respectively.The AUC of ERmax in differentiating sHCC and DN was significantly higher than that of ADC(0.943 vs.0.796,P=0.026﹤0.05).Conclusion Magnetic resonance ADC value and ERmax are both effective in differentiating sHCC and DN,and the ERmax has a relatively higher capacity in the differentiation.