轻微型肝性脑病磁共振扩散加权成像和扩散张量成像的定量研究

目的通过磁共振扩散加权成像(DWI)和扩散张量成像(DTI)定量分析轻微型肝性脑病(MHE)患者脑功能的异常改变,探讨DWI和DTI在MHE中的应用价值。方法30例肝硬化患者经神经心理测试评分量表测试后,分为MHE组16例和无MHE单纯肝硬化组14例,同时选取15例健康志愿者为正常对照组。所有受试者均行DWI与DTI扫描,选取脑内8个部位为感兴趣区,计算各部位的表观扩散系数(ADC)值和各向异性分数(FA)值。结果18例肝硬化患者于T1WI图像上可见到双侧内囊、苍白球对称性高信号。额叶、枕叶白质、胼胝体膝部、胼胝体压部、内囊前肢、内囊后肢、尾状核头部由正常组、单纯肝硬化组至MHE组ADC值逐渐增加,且MHE组的ADC值较肝硬化组和正常组增加,差异有统计学意义(P<0.05);胼胝体膝部和压部的FA值由正常组、单纯肝硬化组至MHE组逐渐降低,差异有统计学意义(P<0.05)。结论DWI与DTI联合应用能够预测肝硬化患者MHE的进展程度,具有潜在的临床价值。

Quantitative study of minimal hepatic encephalopathy with diffusion weighted imaging and diffusion tensor imaging

Objective To explore the value of diffusion weighted imaging(DWI)and diffusion tensor imaging(DTI)in the patients with minimal hepatic encephalopathy(MHE)by quantitative analysis of brain function changes.Methods 30 patients with liver cirrhosis were divided into MHE group(16 cases)and liver cirrhosis group(14 cases)by neuropsychological test,and 15 healthy volunteers were recruited as controls.All the participant underwent DWI and DTI scan.8 cerebral anatomic regions were selected as region of interest and the values of apparent diffusion coefficient(ADC)and fractional anisotropy(FA)were calculated.Results Symmetrical high signal intensity of bilateral internal capsule and globus pallidum were observed in T1WI of 18 liver cirrhosis patients.The ADC values of frontal white matter,occipital white matter,genu and splenium of corpus callosum,anterior and posterior limb of internal capsule and head of caudate nucleus increased significantly from normal control group,liver cirrhosis group to MHE group(P<0.05).The ADC values in MHE group were higher than those in liver cirrhosis group and normal control and group(P<0.05).The FA values of genu and splenium of corpus callosum decreased significantly from normal control group,liver cirrhosis group to MHE group(P<0.05).Conclusion DWI combined with DTI can predict the progress of MHE in the patients with liver cirrhosis and may have potential clinical value.