磁共振波谱成像在轻微型肝性脑病诊断中的意义

Significance of magnetic resonance spectroscopy in diagnosis of minimal hepatic encephalopathy

目的:评价3T磁共振波谱成像(magnetic resonance spectroscopy,MRS)在轻微型肝性脑病(minimal hepatic encephalopathy,MHE诊断中的意义.方法:对30例肝硬化M H E患者、30例非M H E肝硬化患者和性别年龄相匹配3 0例正常对照组左侧顶叶采用单体素氢质子波谱点分辨自旋回波波谱序列(point-resolved echo spin spectroscopy,PRESS)进行MRS扫描,分别计算胆碱(choline,Cho)、肌醇(myo inositol,m Ins)、谷氨酰胺复合物(glutamine Glx)、肌酸(creatine,Cr)及N-乙酰天门冬氨酸(N-acetylaspartate,NAA)的峰下面积,并计算出与Cr比值:Cho/Cr、m Ins/Cr、Glx Cr、NAA/Cr进行3组间参数比较,并分析肝硬化患者顶叶MRS各参数与血氨值是否有相关性.结果:(1)3组间顶叶1H-MRS参数比较,与正常对照组相比,MHE组Cho/Cr及m Ins/Cr降低(P<0.05),Glx/Cr增高(P<0.01),NAA/Cr无变化;MHE组与非MHE肝硬化组比较,MHE组m Ins/Cr降低(P<0.05);(2)肝硬化患者顶叶MRS各参数与血氨值无相关性.结论:MRS对于MHE的诊断具有一定的意义,并与静脉血氨值无相关性.

AIM：To assess the value of 3T magnetic resonance spectroscopy（MRS） in the diagnosis of minimal hepatic encephalopathy（MHE）.METHODS：MRS was performed using pointresolved echo spin spectroscopy（PRESS）sequences in patients with liver cirrhosis with MHE（n = 30） and without MHE（n = 30）,and age- and sex-matched healthy controls（n = 30）.The choline（Cho）,myo-inositol（mlns）,glutamine（Glx）,creatine（Cr） and N-acetylaspartate（NAA） at the left parietal lobe were determined at MRS.The metabolic ratios of Cho/Cr,mIns/Cr,Glx/Cr and NAA/Cr were calculated,and then compared among the three groups.The correlation of the cerebral metabolite ratios with venous ammonia values was also analyzed.RESULTS：There were decreased mIns/Cr and Cho/Cr（P 〈 0.05） and elevated Glx/Cr（P 〈0.01） in patients with MHE compared to the normal control group.There was no significant difference in NAA/Cr among the three groups.Compared with the no-MHE group,the patients with MHE showed significantly decreased mIns/Cr in the left parietal lobe（P 〈 0.05）.No statistical correlation between metabolite ratios and venous ammonia values was found.CONCLUSION：3T MRS may be of value in the diagnosis of MHE and there is no statistical correlation between metabolite ratios and venous ammonia values.