中文摘要：

目的利用静息功能磁共振成像（fMRI）观察肝性脑病（hepatic encephalopathy,HE）患者脑缺省模式网络（default-mode network,DMN）的改变。资料与方法对12例HE患者和14名健康自愿者（对照组）行静息状态下fMRI,利用独立成分分析方法 ,分离得到各自的脑DMN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HE患者静息状态下脑DMN的改变。结果 HE患者组经校正后左侧海马功能连接明显下降。与对照组组间分析后,HE患者大部分脑DMN脑区功能连接度降低,包括：双侧内侧前额叶、双侧楔前叶、左侧后扣带回、左侧海马旁回、右侧角回。结论静息fMRI可用于观察HE患者脑DMN的改变。HE患者大部分脑DMN脑区功能连接度下降,提示HE患者的大脑内源性功能组织发生损伤。

英文摘要：

Objective To investigate the alteration of the brain default-mode network（DMN）in the patients with hepatic encephalopathy（HE）using resting functional MRI,and to explore its underlying clinical significance.Materials and Methods Twelve HE patients and fourteen age-matched normal controls underwent standard resting state functional MRI scan.The DMN were picked out after separation of independent component analysis.One and two-sample t-tests were used to observe the changes of the DMN between the patients and controls.Results The functional connectivity of HE patients in the left hippocampal cortex decreased obviously after FDR corrected.Comparison results revealed that there was significantly reduced functional connectivity in the bilateral medial prefrontal cortex,bilateral precuneus,left posterior cingulate cortex,left parahippocampal cortex,and right angle gyrus in HE patients.Conclusion Resting state functional MRI can be used to observe the DMN changes in HE patients.In HE patients,there is a reduced DMN functional connectivity in the widespread regions,which reveals the endogenous damage in the brain functional organization.