中文摘要：

目的利用静息功能磁共振成像（fMRI）观察轻微型肝性脑病（MHE）患者脑缺省模式网络的改变。方法对14例MHE患者和14名正常对照者行静息状态下的功能磁共振扫描,利用独立成分分析方法,分离得到各自的脑缺省模式网络脑区,各组进行单样本t检验组内分析和两样本t检验组间分析,观察MHE患者静息状态下脑缺省模式网络的改变。结果MHE患者和正常对照组均显示出典型的静息态脑缺省模式网络空间分布模式。但与正常对照组相比,MHE患者大部分脑缺省模式网络脑区功能连接降低,包括：左侧后扣带回、双侧前扣带回、双侧额中回、左侧海马旁回;而右侧楔前叶的功能连接较正常对照组升高。结论静息状态下,MHE患者大部分脑缺省模式网络脑区功能连接度下降,而楔前叶增加,反映了MHE患者的大脑内源性功能组织发生损伤。静息fMRI可用于观察MHE患者脑缺省模式网络的改变。

英文摘要：

Objective To investigate the alteration of the default-mode network（DMN）in the patients with minimal hepatic encephalopathy（MHE）using resting functional MRI,and to explore its underlying clinical significance.Methods Fourteen MHE patients and 14 age-matched normal controls underwent standard resting state functional MRI scan.The components representing DMN were picked out after separation of independent component analysis.One and two sample t-tests were used to observe the changes of DMN in the patients in contrast to the controls.Results Typically spatial distributions of the DMN were found in both MHE patients and controls.Comparison results revealed that there was significantly reduced functional connectivity in the left posterior cingulate cortex,bilateral anterior cingulate cortex,bilateral medial prefrontal cortex,left parahippocampal cortex in MHE patients,while functional connectivity increased in the right precuneus.Conclusion Resting state functional MRI can be used to observe DMN changes in MHE patients.In MHE patients,there is reduced DMN activation in the widespread regions,while the activation of right precuneus increases.