MRI技术对术前评估肝细胞癌病理分化程度的分析

Analysis of preoperative evaluation of pathological differentiation of hepatocellular carcinoma by magnetic resonance imaging

目的探讨磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)和扩散加权成像(diffusion weighted imaging,DWI)术前评估肝细胞癌(hepatocellular carcinoma,HCC)病理分化程度的诊断价值。方法选取44例术前行MRI扫描的肝细胞癌患者,以病理结果分为低分化(n=16)、中分化(n=14)和高分化(n=14)三组。测量肿瘤实质部分的DWI成像参数:表观扩散系数(apparent diffusion coefficient,ADC)以及DKI成像参数:各向异性分数(FA)、平均扩散系数(MD)和平均扩散峰度(MK),比较不同组别各参数值的差异及相关性分析。采用ROC曲线评价DWI和DKI成像参数的诊断效能。结果由2位医师测量各参数值的一致性较好(Alpha均>0.85)。三组间的ADC、MD和MK值差异有统计学意义(F=6.411,10.30,4.713;P=0.004,<0.001,0.014);HCC的病理分化程度与ADC、MD值呈正相关(r=0.425,P=0.004;r=0.526,P<0.001),与MK值呈负相关(r=-0.389,P=0.009)。当MD值的阈值取1.687×10^(-3)mm^(2)/s时,鉴别低、高分化HCC的敏感度、特异度分别为87.50%,71.43%,诊断效能最佳(AUC=0.844,P=0.001)。结论与DWI技术相比,DKI对术前评估HCC病理分化程度的诊断效能更佳。

Objective To comparatively analyze the value of diffusion kurtosis imaging(DKI)versus diffusion weighted imaging(DWI)in preoperative evaluation of the pathological differentiation of hepatocellular carcinoma(HCC).Methods 44 patients with HCC scanned by MRI before operation were selected in this work.They were divided into three groups:the poorly(n=16),the moderately(n=14)and the well(n=14)differentiated HCC by the pathological results as the standard.The apparent diffusion coefficient(ADC)of DWI imaging parameters of tumor parenchyma and the imaging parameters of DKI including anisotropy fraction(FA),mean diffusion coefficient(MD)and mean diffusion kurtosis(MK)were measured and compared among different HCC grades.The diagnostic efficiency of DWI and DKI imaging parameters were evaluated by receiver operating characteristic(ROC)curve.Results The consistency of the parameters measured by the two physicians was good(Alpha>0.85).There were significant differences in those parameters for ADC,MD and MK values among the three groups(F=6.411,10.30,4.713;P=0.004,<0.001,0.014).The degree of pathological differentiation was positively correlated with the values of ADC and MD(r=-0.425,P=0.004;r=-0.526,P<0.001),and negatively correlated with the value of MK(r=-0.389,P=0.009).When the threshold of MD value was 1.687×10^(-3)mm^(2)/s,the sensitivity and specificity of differentiating poorly and well differentiated HCC were 87.50%and 71.43%respectively,and the diagnostic efficiency was the best(AUC=0.844,P=0.001).Conclusion Compared with traditional DWI,DKI can more effectively identify poorly and well differentiated HCC.