~1H-MRS and Diffusion Tensor Imaging Study in Minimal Hepatic Encephalopathy / 实用放射学杂志

ABSTRACT

Objective To evaluate the value of proton magnetic resonance spectroscopy(~1H-MRS))and diffusion tensor imaging(DTI)in minimal hepatic encephalopathy(MHE).Methods Twenty-nine with cirrhosis(15 cases with MHE diagnosed according to number-connection test A and digital symbol test and 14 age-matched controls underwent ~1H-MRS and DTI examinations.~1H-MRS of left basal ganglia were acquired using STEAM sequences.Peak area of each metabolite,including NAA,Cr,Cho,mIns and Glx and their ratios to Cr were measured,respectively.Fractional anisotropy(FA),mean diffusivity(MD)were calculated in deep gray matter nuclei and mainly white matter regions in both cerebral hemispheres.The MD and FA values from different regions in different groups were compared.Results NAA/Cr and Glx/Cr levels showed no significant difference among the groups(P＞0.05).Ratios of mIns/Cr and Cho/Cr showed no differences in MHE group compared to controls(P＞0.05),whereas were significantly different in MHE and cirrhosis without MHE(P＜0.05).The MD values from different regions had a significant difference among various groups(P＜0.05),and there were no significant changes in FA among the groups(P＞0.05).Significantly increased MD was found in five regions of brain in MHE and only caudate nuclei in cirrhosis without MHE compared to controls.Conclusion Patients with MHE have abnormal metabolite changes in basal ganglia;the increase in MD with no concomitant changes in FA in cirrhosis with MHE that indicates the presence of reversible interstitial brain edema.MRS and DTI may be sensitive tests for detecting MHE.