磁共振波谱分析在轻微型肝性脑病诊断中的应用

目的 :评价3T磁共振1H-MRS(1H-magnetic resonance spectroscopy)在轻微型肝性脑病(minimal hepatic encephalopathy,MHE)诊断中的应用。方法:对30例MHE患者和26例无MHE的肝硬化患者采用单体素点分辨自旋回波波谱(stimulated echo acquisition mode spectroscopy,STEAM)序列进行左侧基底节区的MRS扫描,然后分别计算N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)、肌醇(mI)和谷氨酰胺复合物(Glx)峰下面积,算出NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr,然后与对照组的26例健康体检者进行比较。结果:MHE患者左侧基底节区的Cho/Cr、MI/Cr比对照组低,差异显著(P值分别为<0.01和<0.001),而Glx/Cr比对照组明显升高(P<0.005)。与无MHE的肝硬化患者比较而言,Glx/Cr与Cho/Cr也有显著差异(P<0.01,P<0.005)。而无MHE的肝硬化患者和对照组的健康体检者相比,MI/Cr也存在明显差异(P<0.001)。左侧基底节区的Glx/Cr比值与血氨浓度呈正相关,Cho/Cr和MI/Cr的比值与血氨浓度呈负相关。结论:3T场强磁共振MRS检查显示MHE患者左侧基底节区Cho、MI水平降低,Glx水平升高,左侧基底节区MRS与血氨浓度相关,可以作为检测肝硬化患者脑部出现病变的敏感部位,MRS对于MHE的诊断具有参考价值。

Application of Magnetic Resonance Spectroscopy in Diagnosis of Minimal Hepatic Encephalopathy

To study the value of 3T proton magenetic resonance spectroscopy （MRS） in diagnosis of minimal hepatic encephalopathy（MHE）. MRS was performed using stimulated echo acquisition mode spectroscopy（STEAM） sequences in 30 with MHE and 26 without MHE cirrhotic patients. Peak area of each metabolite, including NAA, Cr, Cho, mI, Glx and their ratios to Cr were compared with venous ammonia of control group of 26 healthy subjects. Compared with controls, the patients with MHE showed significantly decreased Cho/Cr, MI/Cr and significantly increased Glx/Cr in the basal ganglia. Glx/Cr and Cho/Cr were significant]y different in patients without and with MHE （P〈0.01, P〈 0.005）. MI/Cr was significantly different in patients without MHE from the controls（P〈0.001）. MRS shows Cho and MI decreases and Glx increases in the basal ganglia in patients with MHE. MRS may be of value in diagnosis of MHE.