MR扩散加权成像术前评估肝细胞肝癌分化程度的应用价值

目的探讨常规DWI单指数模型与体素内不相干运动双指数模型定量参数在肝细胞肝癌分化程度的价值。方法前瞻性地研究102例肝细胞肝癌患者,经手术病理证实高分化40例,中分化32例,低分化30例。所有患者术前均行胸部常规MRI序列和IVIM-DWI序列扫描,经后处理工作站处理图像,测量病灶的表观扩散系数(ADC,Apparent Diffusion Coefficient)、慢速表观扩散系数(D,slow Apparent Diffusion Coefficient)、快速表观扩散系数(D*,fast Apparent Diffusion Coefficient)、快速扩散所占总体扩散的百分比(f,fraction of fastapparent diffusion coefficient)。采用单因素方差分析比较肝细胞肝癌不同分化程度之间参数的差异;采用受试者工作特征曲线(Receiver Operating Characteristic curve,ROC曲线)评价各参数鉴别低分化肝细胞肝癌的诊断价值。结果不同分化程度肝细胞肝癌之间的ADC,D值的差异均有统计学意义(F值分别为:13.939,31.035;均P<0.01),不同分化程度肝细胞肝癌之间的D*,f值的差异均无统计学意义(F值分别为:1.473,2.477;均P>0.05);各参数中D值鉴别低分化肝细胞肝癌的诊断效能最高,ROC曲线下面积(Areas under curves,AUC)0.928、阈值为0.982×10-3 mm2/sec、敏感度93.3%、特异度87.5%。结论常规DWI序列与IVIM-DWI序列定量参数有助于术前临床评估肝细胞肝癌分化程度,其中IVIM-DWI参数值D具有最高的诊断价值。

Preoperative Evaluation in Hepatocellular Carcinoma Pathological Differentiation by Diffusion-weighted MR Imaging

Objective To investigate the value of quantitative parameters of conventional DWI model and bi-exponential Intravoxel incoherent motion(IVIM) model in pathological differentiation of hepatocellular carcinoma(HCC). Methods A prospective study of 102 patients with hepatocellular carcinoma confirmed with surgically confirmed HCCs. And well differentiated in 40 cases, moderately differentiated in 32 cases, poorly differentiated in 30 cases. All patients were underwent conventional chest MRI and IVIM-DWI sequences before operation. The images were processed by postprocessing workstation. Apparent Diffusion Coefficient(ADC), slow Apparent Diffusion Coefficient(D), fast Apparent Diffusion Coefficient(D*) and fraction of fast apparent diffusion coefficient(f) were independently measured. The differences of parameters were compared among the pathological differentiations by using analysis of variance(ANOVA). Receiver operating characteristic(ROC) analysis was performed to evaluate the diagnostic efficiency of distinguishing poorly differentiated hepatocellular carcinoma. Results The differences of ADC and D in different pathological differentiations were statistically significant(F=13.939,31.035;respectively, all P<0.01). And there were no significant differences in D*, f values.(F=1.473, 2.477;respectively, all P>0.05). The diagnostic efficiency of D value in differentiating poorly differentiated hepatocellular carcinoma with the area under the ROC curve(AUC) was 0.928, the sensitivity, 93.3%, the specificity, 87.5%. Conclusion The quantitative parameters of conventional DWI model and IVIM model are helpful for preoperative clinical evaluation of hepatocellular carcinoma pathological differentiation, and the value of IVIM-derived D value has best diagnostic value.