肝硬化患者脑代谢的磁共振波谱成像研究

Cerebral Metabolic Changes in Patients with Hepatic Cirrhosis:Magnetic Resonance Spectroscopic Study

目的利用磁共振波谱成像(MRS)评价肝硬化患者脑内代谢物的异常改变及其与临床静脉血氨值和神经心理学测试结果之间的相关性。资料与方法52例经病理学和/或临床检查证实的肝硬化患者和30例健康志愿者纳入本研究。所有研究对象在MRI检查前进行数字连接试验-A(NCT-A)、数字符号试验(DST)以及符号数字试验(SDT)。均行扣带回和右侧基底节的单体素氢质子波谱扫描,给出各代谢物曲线下面积与Cr的比值。记录肝硬化患者的静脉血氨值。结果患者组扣带回和基底节出现Cho/Cr降低、(Cho+mIns)/NAA降低、Glx/Cr升高、mIns/Cr降低。扣带回的mIns/Cr与Child分级(r=-0.496,P<0.001)及HE分级(r=-0.313,P<0.05)之间均存在相关性;而基底节的Cho/Cr(r=-0.497,P<0.001)、mIns/Cr(r=-0.341,P<0.05)和(Cho+mIns)/NAA(r=-0.276,P<0.05)与Child分级之间有显著负相关,Glx/Cr与HE分级之间有正相关性(r=0.385,P<0.05)。扣带回与右侧基底节的MRS指标与血氨之间存在负相关关系。扣带回的Glx/Cr与NCT-A有正相关关系(r=0.366,P=0.028)。结论肝硬化患者扣带回和基底节存在生化代谢的异常改变,扣带回可作为检测肝硬化患者脑改变的一个敏感部位。

Objective To evaluate cerebral metabolic changes in patients with hepatic cirrhosis and healthy subjects, and correlate the cerebral metabolic changes with venous ammonia concentration and neuropsychiatric tests scores. Methods 52 patients with hepatic cirrhosis proven by pathology, biopsy, and/or clinical examinations and 30 healthy volunteers have been investigated. All subjects performed three kinds of neuropsychological （NP） tests including number-connection test part A （NCT-A）, digital symbol test （DST）, and symbol digital test （SDT） before magnetic resonance （MR） imaging. Localized magnetic resonance spectra were acquired in the cingulate cortex and basal ganglia with single voxel 1-hydrogen MR spectroscopy. Metabolite quantification was performed and the ratio of all metabolites was acquired using creatine （Cr） as a reference. Venous ammonia concentration was measured in 44 cases. Results Compared to healthy controls, MR spectroscopic results showed a statistically significant decrease in choline （Cho）/Cr （ P 〈 0. 001 ） , myo - inositol （mIns）/Cr （ P 〈 0. 001 ） , and Cho and mIns/N-acetylaspartate （NAA） （ P 〈 0. 001 ）and an increase in glutamate/glutamine （Glx） （P 〈0.001 ） in cingulate cortex and basal ganglia in patients. The NP results indicated a significantly negative correlation between mIns/Cr in cingulate cortex and Child-Pugh scale （ r = - 0.496, P 〈 0. 001 ） and hepatic encephalopathy （ HE ） grades （ r = - 0. 313, P 〈 0.05 ）. There was also a significantly negative correlation between Cho/Cr （ r = - 0. 497, P 〈 0.001 ）, mIns/Cr （ r = - 0. 341, P 〈 0.05 ）, and Cho and mIns/NAA （r = - 0. 276, P 〈 0.05 ） of basal ganglia and Child-Pugh scale. However, there was a significantly positive correlation between Glx/Cr and HE grades （ r = 0. 385, P 〈 0.05 ）. The results also showed a significantly negative correlation between metabolite changes in both cingulate cortex and basal ganglia and the venous ammonia concentration and a significantly positive correlation between Glx/Cr of cingulate cortex and NCT-A （ r = 0. 366, P = 0.028）. Conclusion The metabolic changes could be observed in the cingulate cortex and basal ganglia in patients with hepatic cirrhosis, and cingulate cortex might be a sensitive location in detecting HE.