Investigation Of Magnetic Resonance Spectroscopy In The Diagnosis Of Minimal Hepatic Encephalopathy

Objective:The aim of this work was to investigate the value of 3T proton magnetic resonance spectroscopy (’H-MRS) in diagnosis of minimal hepatic encephalopathy (MHE).Methods:1、Patients were selected from the Department of Hepatobiliary and Pancreatic Medicine at the Second Affiliated Hospital of Kunming Medical University from May 2013 to December 2014. All patients met the diagnostic criteria of liver cirrhosis by clinical, image and laboratory findings. The NCT-A and DST tests were performed in all patients, two were positive diagnosis of liver cirrhosis with MHE, of which at least a negative for non MHE patients with cirrhosis. At the same time some healthy individuals matched for sex and age were selected as control. The study was approved by the regional Ethics Committee of hospital and informed consent was obtained from all the participants before enrolment.2、MRI scan and MRS was performed using point-resolved echo spin spectroscopy (PRESS) sequences in liver cirrhosis with MHE(n=27) and with no MHE(n=24) group and healthy control group(n=27). The goal of MRI scan is to exclude other intracranial disease and clear whether all subjects had abnormal signal in basal ganglia. The choline(Cho), myoinositol (mIns), 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, then compared among three groups. Correlated the cerebral metabolite ratio(Cho/Cr, mIns/Cr and NAA /Cr) with Glx/Cr.Results:1、Part of patients with cirrhosis was showed that there were high signal on T1WI in bilateral basal nuclei. There was statistical significance in abnormal signal on T1WI in bilateral basal nuclei among there groups (F=51.015, P<0.01)2、There was decreased Cho/Cr (P<0.05) and mIns/Cr (P<0.01) and elevated Glx/Cr(P<0.01) in patients with MHE compared to control group. Results Compared with the no MHE group, the patients with MHE showed significantly elevated Glx/Cr in the left parietal lobe (P<0.05), There was no significant difference in mIns/Cr、 Cho/Cr and NAA/Cr between two groups. Results Compared with the control group, the no MHE group showed significantly decreased mIns/Cr and elevated Glx/Cr in the left parietal lobe(P<0.01). There was no significant difference in Cho/Cr and NAA/Cr between two groups(P>0.05).3、There is a negative correlation between Glx/Cr and mIns/Cr(P<0.01, R=-0.357) in the left parietal lobe in patients with liver cirrhosis. No statistical correlation between metabolite ratio(Cho / Cr、NAA/Cr) and Glx/Cr was found.Conclusion:1、1H-MRS can noninvasively detect metabolite levels in brain cells, MRS shows that increased Glx/Cr ratios and decreased Cho/Cr and mIns/Cr ratios in the left parietal lobe is the characteristics of MHE; And increased Glx/Cr ratios and decreased mIns/Cr are more sensitive.2、Patients with cirrhosis had metabolic disorder in brain, MRI shows that part of patients may had a high signal on T1WI in basal ganglia region, mainly in the globus pallidus, may be associated with manganese deposit.3、The pathogenesis of hepatic encephalopathy was complex, in addition to ammonia poisoning causing brain astrocyte edema, Cho, Glx and mIns are involved in cell metabolism, There were many other factors are involved in the occurrence of hepatic encephalopathy.4、1H-MRS can distinguish between liver cirrhosis with MHE group, no MHE group and the normal control group,’H-MRS in the diagnosis of MHE had important significance. 1H-MRS may become a new tool for the diagnosis of MHE and provide a new method for the future clinical research on MHE.