慢性高原病脑部多体素1H-MRS研究

目的利用多体素氢质子磁共振波谱成像(hydrogen proton magnetic resonance spectroscopy,¹H-MRS)探讨慢性高原病(chronic mountain sickness,CMS)长期缺氧状态下脑部代谢物的特点,并比较各代谢物与血液指标之间的相关性。材料与方法前瞻性纳入青海大学附属医院经临床确诊为CMS的17例男性患者作为实验组,年龄(53.29±9.03)岁,居住海拔(3989.12±937.45)m,血红蛋白(hemoglobin,HGB)(224.35±11.81)g/mL,并招募与实验组年龄及居住海拔相匹配的18名健康男性志愿者作为对照组,年龄(48.61±8.76)岁,居住海拔(3674.94±634.27)m,HGB(156.67±9.46)g/mL。采用Siemens Prisma 3.0 T MR扫描仪20通道头颅线圈对所有受试者行常规头颅MRI及多体素;H-MRS检查,通过Syngo.via后处理软件获得;H-MRS图,ROI选取双侧额叶及海马区,并获得相应脑区N-乙酰天门冬氨酸/肌酸(NAA/Cr)、胆碱/肌酸CHo/Cr、乙酰天门冬氨酸/胆碱(NAA/CHo)、乳酸/肌酸(Lac/Cr)的比值。结合独立样本t检验及非参数曼-惠特尼U检验以比较两组间代谢物相对浓度差异,然后将CMS组双侧额叶及海马区各代谢物比值与血液生化指标作相关性分析。结果(1)两组受试者年龄、长期居住海拔差异均无统计学意义(P>0.05),而与对照组相比,CMS组HGB、红细胞计数(red blood cell count,RBC)、血细胞比容(hematocrit,HCT)增高,血小板(blood platelet,简称PLT)减低,差异均有统计学意义(P<0.01);(2)与对照组相比,CMS组双侧额叶及海马区NAA/Cr及NAA/CHo均减低(P<0.05),Lac/Cr增高(P<0.05),差异均具有统计学意义;(3)与对照组相比,CMS组双侧额叶及双侧海马区CHo/Cr均增高(P>0.05),差异无统计学意义;(4)CMS组右侧额叶及左侧海马CHo/Cr与RBC明显正相关,左侧额叶CHo/Cr与HCT低度正相关,右侧额叶及左侧海马Lac/Cr与HCT低度正相关。结论CMS长期缺氧状态下脑组织局部代谢物改变,神经元受损,无氧代谢增加,且这些代谢物的改变与血液指标呈一定的相关性,可为临床后续进一步预防或干预CMS患者脑损害提供影像学证据及监测指标。

Study on multi-voxel 1H-MRS in brain of chronic mountain sickness

Objective:Using multi-voxel hydrogen proton magnetic resonance spectroscopy(;H-MRS)to explore the characteristics of brain metabolites in chronic mountain sickness(CMS)under long-term hypoxia,and compare the metabolites with correlations between blood parameters.Materials and Methods:Seventeen male patients who were diagnosed with CMS at Qinghai University Affiliated Hospital were collected as the experimental group,with age of(53.29±9.03)years,living altitude of(3989.12±937.45)meters and hemoglobin(HGB)of(224.35±11.81)g/mL.The control group consisted of eighteen healthy volunteers with the same age,gender and living altitude as the experimental group.The living altitude was(3674.94±634.27)meters,and the HGB was(156.67±9.46)g/mL.All cases were examined by routine head MRI and multi-voxel;H-MRS 3 D chemical shift imaging technology(CSI-SLASER)with20-channel head coil of Siemens Prisma 3.0 T MR scanner.;H-MRS images were obtained by Syngo.via post-processing software,bilateral frontal lobe and hippocampus were selected as ROIs.The ratios of N-acetylaspartate/creatine(NAA/Cr),choline/creatine(CHo/Cr),N-acetylaspartate/choline(NAA/CHo)and lactic acid/creatine(Lac/Cr)were measured.Then the correlation between the ratio of each metabolite in bilateral frontal lobe,hippocampus and blood biochemical indexes in CMS group was analyzed.Results:(1)There was no significant statistical difference in age and living altitude between the two groups(P>0.05),but the HGB,red blood cell count(RBC)and hematocrit(HCT)in the two groups were significantly higher than those in the control group,while platet(PLT)was lower than those in control group,with significant differences(P<0.01).(2)Compared with the control group,NAA/Cr and NAA/CHo in bilateral frontal lobe and bilateral hippocampus decreased,Lac/Cr increased in CMS group,which were statistically significant(P<0.05).(3)Compared with the control group,the CHo/Cr of bilateral frontal lobe and bilateral hippocampus increased(P>0.05),but there was no statistical significance between the two groups.(4)In CMS group,CHo/Cr in the right frontal lobe and left hippocampus was positively correlated with RBC,CHo/Cr in the left frontal lobe was positively correlated with HCT,Lac/Cr in the right frontal lobe and left hippocampus was positively correlated with HCT.Conclusions:Under the long-term hypoxia condition of CMS,local metabolites in brain tissues are changed,neurons are damaged and anaerobic metabolism increased,and the changes of these metabolites are correlated with blood indexes to a certain extent,which can provide imaging evidence and monitoring indicators for further prevention or intervention of brain damage in CMS patients.