轻微型肝性脑病的1H-MRS与临床及神经心理学测定的相关性研究

目的 利用MRS评价轻微型肝性脑病（MHE）病人扣带回是否出现同基底节相似的代谢物改变，评价其代谢物比值与临床神经心理学测试及静脉血氨值之间的关系。方法 24例MHE病人和30例正常对照者均完成3项临床神经心理学测试，包括数字连接试验-A（NCT-A）、数字符号试验（DST）及符号数字试验（SDT）。进行了扣带回和右侧基底节的单体素点分辨自旋回波波谱序列扫描。分别计算各代谢物，包括N-乙酰天门冬氨酸（NAA），肌酐（Cr），胆碱（Cho），肌醇（mI），谷氨酰胺复合物（Glx）的峰下面积，计算NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr及Cho＋mI/NAA比值。21例在MR检查前后一周内进行了静脉血氨水平测定。结果 与正常对照组相比，MHE组扣带回的Cho/Cr、mI/Cr及Cho＋mI/NAA降低，Glx/Cr比值升高，右侧基底节的Cho/Cr、mI/Cr及Cho＋mI/NAA比值降低，Glx/Cr和NAA/Cr无改变。Pearson相关分析显示，扣带回的Cho/Cr比值与SDT，mI/Cr及Cho＋mI/NAA与NCT-A、DST及SDT之间，Glx/Cr与NCT-A及SDT存在相关关系，其中以mI/Cr与3种神经心理学测试结果之间的相关性最显著。右侧基底节仅Cho/Cr和mI/Cr与各神经心理学测试结果之间存在相关关系。扣带回的Cho＋mI/NAA与静脉血氨值之间存在显著的负相关关系（r=-0.552，P=0.009）。结论 MHE病人扣带回出现代谢物的异常改变，扣带回的mI/Cr比值与神经心理学测试之间存在更明显的相关关系，提示可能能够更好地预测MHE的发生。

1H-MRS of minimal hepatic encephalopathy: correlation with clinical and neuropsychiatric tests

Objective To evaluate whether cingulate cortex has a similar change as basal ganglia in minimal hepatic encephalopathy (MHE) using magnetic resonance spectroscopy (MRS), the correlation between the metabolite ratio and clinical neuropsychiatric tests and venous ammonia. Methods Twenty-four patients with MHE and 30 controls completed 3 kinds of neuropsychiatric tests, including number-connection test A (NCT-A), digital symbol test (DST), and symbol digital test (SDT). MRS of cingulated cortex and right basal ganglia were acquired using PRESS sequences in all subjects. Peak area of each metabolite, including NAA, Cr, Cho, mI, and Glx and their ratios to Cr, and Cho+mI/NAA were computed, respectively. Venous ammonia was measured in 21 patients with MHE. Results Compared with controls, patients with MHE showed decreased Cho/Cr, mI/Cr, and Cho+mI/NAA in cingulate cortex and right basal ganglia, elevated Glx/Cr in cingulate cortex. Pearson correlation analysis displayed that there were significant correlations between the ratio of Cho/Cr and SDT, the ratios of mI/Cr and Cho+mI/NAA and NCT-A, DST, and SDT, and the ratios of Glx/Cr and NCT-A and SDT in cingulate cortex. mI/Cr had the strongest correlation with neuropsychiatric test results. In right basal ganglia, there was a significant correlation between the ratios of Cho/Cr and mI/Cr and all neuropsychiatric tests. There was a strong correlation between the ratio of Cho+mI/NAA in cingulate cortex and venous ammonia (r=-0.552, P=0.009). Conclusion Patients with MHE have the abnormal metabolite changes in cingulate cortex; there is a strong correlation between the ratio of mI/Cr in cingulate cortex and the neuropsychiatric tests, indicating MRS abnormalities of cingulate cortex may better predict the presence of MHE.