自闭症的常规MRI和1H-MRS表现

目的 探讨常规MR成像和1H MR波谱(MRS)在自闭症诊断中的价值.资料与方法 回顾性分析12例自闭症患者的全脑常规MR扫描及其中8例患者额叶和海马的多体素2D 1H MR波谱扫描表现.结果 常规MR扫描发现3例患者的顶叶白质在FLAIR上出现斑片状高信号.1H MRS分析发现5例患者额叶的NAA/Cho明显下降(NAA/Cho<1),其中1例患者的左侧额叶出现Lac峰;另外有2例患者海马的NAA/Cho出现下降(NAA/Cho<1).结论 常规MR成像和1H MRS可发现部分自闭症患者脑组织异常.     

海洛因依赖者前额叶皮层与海马温度改变的磁共振波谱测量

目的 探讨磁共振波谱(MRS)技术测量海洛因依赖者前额叶皮层与海马温度变化的可行性及意义.方法 对18例处于戒断治疗期的海洛因依赖者和18例健康志愿者(对照组)分别于静息态和视觉刺激(呈现海洛因相关图片)诱导渴求状态下进行单体素MRS扫描,测量前额叶皮质和双侧海马N-乙酰基天门冬氨酸(NAA)化学位移值,通过修正后的温度-NAA化学位移方程,计算其脑温度.结果 海洛因依赖组静息态前额叶皮层脑温度较对照组上升,差异有统计学意义(P<0.05),并且其脑温度值与吸食总量呈正相关(P<0.05);但比较静息态与视觉刺激态前额叶皮层及海马温度无显著统计学差异(P>0.05).结论 MRS可无创性测量脑温度,脑温度的异常改变有助于探讨药物成瘾与渴求机制.     

磁共振波谱在不同认知功能损害中的应用

目的：探讨轻度认知功能障碍(MCI)患者、阿尔茨海默病(AD)患者、正常认知(NC)者3组人群海马区代谢物比值的区别。方法收集 MCI 组(30例)、AD 组(28例)及 NC 组(30例)行双侧海马区氢质子磁共振波谱(1 H MRS)检查,比较 MCI 组、AD组和 NC 组左右两侧各组间 NAA/Cr、Ins/Cr、NAA/Ins、Cho/Cr 比值差别。结果MCI 组和 AD 组双侧 NAA/Cr 比值均明显低于NC 组,经统计学分析有显著性差异(P 值均<0.05)。MCI 组、AD 组右侧 Ins/Cr 比值、NAA/Ins 比值分别与 NC 组有显著性差异(P 值均<0.05)。MCI 组、AD 组和 NC 组左侧 Ins/Cr、NAA/Ins 比值3组间比较均有显著性差异(P 值均<0.05)。结论1 H MRS 作为无创性诊断技术,在早期 MCI、AD 诊断及鉴别诊断中具有较高的敏感性。     

SURF1基因突变与PDHA1基因缺陷导致的Leigh病的MRS特点

目的 探讨线粒体脑肌病中Leigh病的SURF1基因突变及PDHA1基因突变的磁共振波谱(MRS)特点,及Leigh病基因突变类型与MRS的关系.方法 12例Leigh病患者经基因检查8例为SURF1基因突变,4例为PDHA1基因缺陷.对这12例Leigh病和38例正常对照者进行2D-MRS检查和常规MRI检查;比较SURF1基因突变组、正常对照组和PDHA1基因缺陷组的苍白球、丘脑和尾状核区域的Cho/Cr、NAA/Cr、Lac/Cr及MI/Cr比值的差异.结果 12例Leigh病中,常规MRI显示6例有脑白质异常,7例有灰质核团异常,1例有脑萎缩.MRS结果显示:SURF1基因突变组与PDHA1基因缺陷组比较在丘脑区的Lac/Cr、MI/Cr比值(P<0.05)和尾状核区的NAA/Cr比值有统计学差异(P<0.05).SURF1基因突变组与正常对照组比较苍白球区的Lac/Cr比值(P=0.019),丘脑区4个比值(P<0.01),及尾状核区的Cho/Cr、NAA/Cr、Lac/Cr比值(P<0.05)均有统计学差异.PDHA1基因缺陷组与正常对照组在基底节各核团的比值均无统计学差异.结论 SURF1基因突变与PDHA1基因缺陷的MRS代谢比值的差异,反映了2种不同基因突变类型之间的代谢差别.     

阻塞性睡眠呼吸暂停综合征病人脑损害的MRS研究

目的探讨MRS在阻塞性睡眠呼吸暂停综合征(OSAS)中的应用价值。方法应用1.5T超导型MR设备对21例重度、14例轻中度OSAS病人及性别、年龄相匹配的15例健康对照者的双侧额叶及左侧颞-顶-枕叶交界区、左侧海马行单体素氢质子波谱——点分辨自旋回波波谱序列扫描。结果①左侧额叶NAA/Cr,OSAS重度组明显小于健康对照组(P=0.004);右侧额叶NAA/Cr,轻中度组(P=0.007)及重度组(P=0.002)均小于健康对照组;左侧海马NAA/Cr,OSAS病例组较健康对照组有减小的趋势。②右侧额叶mI/Cr,OSAS轻中度组(P=0.000)及重度组(P=0.008)均大于健康对照组。③左侧额叶Glx/Cr,OSAS重度组明显小于健康对照组(P=0.006);右侧额叶Glx/Cr,OSAS重度组较健康对照组有减小的趋势。结论 MRS分析显示OSAS易累及双侧额叶。MRS可以从代谢水平上评价OSAS的脑损害。     

创伤后应激障碍患者海马活体MR波谱研究

目的探讨创伤后应激障碍（PTSD）患者双侧海马活体MR波谱（MRS）的特点,为创伤后应激障碍的诊断和病因学机制提供线索.方法应用多体素活体MRS成像技术,对12例PTSD患者和12例正常对照者进行波谱分析,检测双侧海马的N-乙酰天门冬氨酸（NAA）,肌酸（Cr）和含胆碱化合物（Cho）峰值,并进行统计学比较.结果PTSD患者左侧海马的NAA/Cr比值明显低于正常对照组（F=9.99,P=0.006）,Cho/Cr比值差异无统计学意义（F=0.36,P=0.55）;右侧海马的NAA/Cr比值、Cho/Cr比值差异均无统计学意义（F=1.44,P=0.25）.性别之间的波谱差异比较无统计学意义（F=0.56,P=0.82）;年龄、受教育时间、PTSD症状严重程度与左侧海马NAA/Cr比值的相关系数分别为0.47、0.35和0.18,差异无统计学意义（P＞0.05）.结论PTSD患者左侧海马存在病理性变化,NAA/Cr比值低于正常人.     

氢质子磁共振波谱在小儿颞叶癫痫研究中的应用

目的 结合MRI和脑电图（EEG）所见，评价氢质子磁共振波谱（^1H MRS)在小儿颞叶癫痫诊断中的价值。方法 对10例颞叶癫痫患儿和8例健康自愿儿用2．0T场强MR扫描系统进行MRI及^1H MRS采集。测定N－乙酰天门冬氨酸（NAA）、胆碱（Cho)、肌酸（Cr)、乳酸（Lac)、肌醇（MI）、谷氨酸及谷氨酰胺（Glu/Gln)等代谢产物。结果 以NAA／（Cr Cho)值为标准，海马硬化侧组及脑电图异常侧组与对照组间比较，差异有显著性意义（平均差异分别为0．7663、0．6190，P＜0．05）。结论 ^1H MRS在小儿颞叶癫痫灶诊断的敏感性高于MRI，且有助于脑电图定位诊断。     

脑白质疏松症的MR扩散加权成像及波谱研究

目的通过MR扩散加权成像(DWI)及MR波谱(MRS)分析脑白质疏松症(LA)的表观扩散值(ADC)和不同代谢产物比值的变化,探讨LA中脑白质缺血过程中出现的病理、生化改变与MR功能成像改变之间的关系。方法30例经常规MRI检查诊断为LA患者,及30例年龄相匹配的正常脑白质表现的患者作为对照组,进行DWI检查,分析病变不同区域ADC值的变化,同时对LA患者进行MRS分析N-乙酰天门冬氨酸(NAA)/肌酸(Cr)、胆碱复合物(Cho)/肌酸(Cr)比值的变化,比较不同位置和不同程度病变在ADC值和代谢变化中的差异。结果LA患者病灶区(双侧侧脑室枕角、体部旁脑白质)ADC值升高与对照组差异有显著的统计学意义(P<0.01),相应病灶区的NAA/Cr均值明显降低,Cho/Cr均值升高,与正常白质比较差异有显著统计学意义(P<0.01),而枕角的NAA/Cr均值低于体部,差异有显著统计学意义(P<0.01)。结论磁共振功能成像能够反映脑白质疏松症发展中的微观结构变化和局部代谢的异常。     

阿尔茨海默病的高场氢质子磁共振波谱研究

目的:探讨阿尔茨海默病(Alzheimer's disease,AD)双侧海马的高场氢质子磁共振波谱(proton magnetic resonance spectroscopy,1H-MRS)的特点.方法:对AD组14例及正常对照组(normal control,NC)10例受试者行T_1WI-3D薄层扫描并进行海马三平面MPR重建,在所得MPR图像上定位双侧海马.采用MRS测定双侧海马N-乙酰天门冬氨酸(N-acetyl aspartate,NAA)、胆碱(choline,Cho)、肌醇(myo-lnositol,mI)和谷氨酸-谷氨酰胺复合物(Glx)与肌酸(ereatine,Cr)的比值.采用SPSS 17.0软件进行统计分析,观察AD组与NC组双侧海马各代谢物比值的差异.结果:AD组双侧海马的NAA/Cr、Glx/Cr比值较NC组降低,其差异具有统计学意义,AD组右侧海马ml/Cr比值较NC组升高具有统计学意义(P<0.05),左侧海马mI/Cr比值有升高趋势.但未达到统计学意义水平,AD组双侧海马Cho/Cr比值与NC组的差异无统计学意义.结论:双侧海马的高场MRS能够检测到AD特征性的代谢物改变.T_1WI-3D扫描行海马三平面MPR重建有助于海马MRS的准确定位,提高图像质量及可信度.     

轻微型肝性脑病的~1H-MRS和磁共振弥散张量成像研究

目的 探讨氢质子波谱(~1H-MRS)及弥散张量成像(DTI)在预测轻微型肝性脑病(MHE)中的价值.方法 29例肝硬化患者及14例年龄相匹配的健康对照者分别进行头部MRS与DTI扫描,其中15例患有MHE(经数字连接试验及数字符号试验测试).采用单体素激励回波采集序列(STEAM)行左侧基底节区MRS扫描,分别计算N-乙酰天门冬氨酸(NAA),肌酸(Cr),胆碱(Cho),肌醇(mIns),谷氨酰胺复合物(Glx)的峰下面积.并计算各自与Cr比值:NAA/Cr、Cho/Cr、mIns/Cr、Glx/Cr.DTI选用平均弥散率(MD)及各向异性分数(FA)作为参数,选取主要的白质及深部灰质共7个部位为感兴趣区,计算各部位MD及FA值.结果 MRS检查结果显示各组间NAA/Cr与Glx/Cr无显著性差异(P＞0.05),MHE组mIns/Cr与Cho/Cr降低,与无MHE组及对照组间有显著性差异(P＜0.05).而无MHE组与正常对照组间mIns/Cr与Cho/Cr无显著性差异(P＞0.05).DTI检查结果发现有与无MHE的肝硬化患者及对照组不同部位MD值间差异有统计学意义(P＜0.05);FA值无显著性差异(P＞0.05).与对照组比较,MHE组脑内5个部位的MD值显著性增加(P＜0.05);无MHE的肝硬化组仅在尾状核部MD值显著增加(P＜0.05).结论 MHE病人基底节区显示的代谢物改变以及脑内MD值增高不伴FA值的异常改变,提示MHE病人存在轻度细胞外间隙脑水肿,MRS及DTI在预测MHE中有一定价值.     

Cerebral MR spectroscopy in neurologically asymptomatic HIV-infected patients

PURPOSE: To detect early metabolic changes in the brain of neurologically asymptomatic HIV-infected patients with normal MR imaging and to find the correlation between 1H MR results and immune status. MATERIAL AND METHODS: Twenty neurologically asymptomatic HIV seropositive patients underwent MR imaging and single-voxel 1H MR spectroscopy (MRS) using a PRESS sequence. For all patients, the signals from N-acetyl-aspartate (NAA), choline-containing compounds (Cho), creatine-phosphocreatine (Cr) and myoinositol (mI) were compared with 32 healthy volunteers as metabolite ratios and metabolite areas to non-suppressed water area ratios. RESULTS: In HIV patients, the NAA/Cho ratio was significantly lower ( p < 0.01), but there were no changes in NAA/Cr ratio. A statistically significant reduction in NAA/H2O and Cr/H2O (both p < 0.05) was observed. For the immune status there was a statistically significant correlation (r=0.47, p<0.05) between CD4 counts and NAA/H2O ratio. A significant increase in Cho/Cr ( p<0.001) and mI/Cr ( p<0.01) ratios in HIV patients was found, but Cho/H2O and mI/H2O concentrations were non-significantly increased. CONCLUSION: These results indicate that neuronal loss and gliosis in HIV-infected patients may be associated with impairment of energy metabolism. The spectral changes found suggest that 1H MRS can be used for early detection of brain damage induced by HIV.     

Volumetric MRI and 1H MRS study of hippocampus in unilateral MCAO patients: relationship between hippocampal secondary damage and cognitive disorder following stroke

Objective

To determine whether hippocampi alter in patients at the recovery stage of middle cerebral artery occlusion (MCAO) and whether the changes of hippocampi involve in the cognitive impairment in such patients.

Meterials and methods

Forty-four patients with unilateral infarction solely in MCAO territory and 44 age-, sex- and education background-matched healthy volunteers were enrolled in this study. All subjects underwent 3-dimensional fast spoiled gradient-echo (3D FSPGR) and sing-voxel proton magnetic resonance spectroscopy (¹H MRS) protocols at a 1.5 T MR scanner. The ratios of n-acetylaspartate/creatine (NAA/Cr) and myo-inositol/creatine (mI/Cr) were obtained by using software integrated in the MR scanner. The hippocampal volumes were estimated by manually measurement.

Results

The volume and NAA/Cr ratio were found significantly decreased and mI/Cr ratio significantly increased in the hippocampus ipsilateral to occluded middle cerebral artery (MCA) as compared with values in the contralateral hippocampus or healthy control. A reduced NAA/Cr ratio was also observed in contralateral hippocampus compared to controls. The shrinkage ratio of hippocampus ipsilateral to MCAO was found related to the Mini–Mental State Examination (MMSE) score.

Conclusion

Our study identified that the hippocampal secondary damage occurred in patients after MCAO, and it could be evaluated noninvasively by volumetric magnetic resonance imaging (MRI) and ¹H MRS. Moreover, the hippocampal secondary damage in MCAO patients indeed contributed to their cognitive impairment.     

In vivo 1H MR spectroscopic findings in traumatic contusion of ICR mouse brain induced by fluid percussion injury

PURPOSE: The purpose of this study was to investigate the proton metabolic differences of the right parietal cortex with experimental brain contusions of ICR mouse induced by fluid percussion injury (FPI) compared to normal controls and to test the possibility that 1H magnetic resonance spectroscopy (MRS) findings could provide neuropathologic criteria in the diagnosis and monitoring of traumatic brain contusions. MATERIALS AND METHODS: A homogeneous group of 20 ICR male mice was used for MRI and in vivo 1H MRS. Using image-guided, water-suppressed in vivo 1H MRS with a 4.7 T MRI/MRS system, we evaluated the MRS measurement of the relative proton metabolite ratio between experimental brain contusion of ICR mouse and healthy control subjects. RESULTS: After trauma, NAA/Cr ratio, as a neuronal marker decreased significantly versus controls, indicating neuronal loss. The ratio of NAA/Cr in traumatic brain contusions was 0.90+/-0.11, while that in normal control subjects was 1.13+/-0.12 (P=0.001). The Cho/Cr ratio had a tendency to rise in experimental brain contusions (P=0.02). The Cho/Cr ratio was 0.91+/-0.17, while that of the normal control subjects was 0.76+/-0.15. However, no significant difference of Glx/Cr was established between the experimental traumatic brain injury models and the normal controls. DISCUSSION AND CONCLUSIONS: The present 1H MRS study shows significant proton metabolic changes of parietal cortex with experimental brain contusions of ICR mouse induced by FPI compared to normal controls. In vivo 1H MRS may be a useful modality for the clinical evaluation of traumatic contusions and could aid in better understanding the neuropathologic process of traumatic contusions induced by FPI.     

Magnetic resonance spectroscopy features of normal-appearing white matter in patients with acute brucellosis

We aimed to evaluate whether the subtle metabolic cerebral changes are present in normal-appearing white matter on conventional MRI, in patients with acute brucellosis, by using MR spectroscopy (MRS). Sixteen patients with acute brucellosis and 13 healthy control subjects were investigated with conventional MRI and single-voxel MRS. Voxels were placed in normal-appearing parietal white matter (NAPWM). N-Acetyl aspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios were calculated. There was no significant difference between the study subjects and the control group in NAA/Cr ratios obtained from NAPWM. However, the Cho/Cr ratios were significantly higher in patients with acute brucellosis compared to controls (p=0.01). MRS revealed metabolic changes in normal-appearing white matter of patients with brucellosis. Brucellosis may cause subtle cerebral alterations, which may only be discernible with MRS. Increased Cho/Cr ratio possibly represents an initial phase of inflammation and/or demyelination process of brucellosis.     

青年抑郁症患者基底节和丘脑3D 1H-MRS研究

目的:探讨青年抑郁症患者基底节和丘脑可能存在的神经生化异常.方法:对44例青年抑郁症患者(抑郁症组)和40例年龄和性别匹配的健康志愿者(对照组)进行常规MRI扫描和三维氢质子MR波谱(3D 1H-MRS)检查,测量双侧基底节和丘脑的 N-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)、肌醇(mI)和肌酸(Cr)的绝对值,并计算它们与Cr的比值.对两组实验对象各代谢物及其比值进行统计学分析.结果:①抑郁症组双侧豆状核和尾状核头部Cho/Cr、mI/Cr明显高于对照组,差异有显著性意义(P＜0.05),而NAA/Cr在两组间差异无统计学意义(P＞0.05);②抑郁症组丘脑NAA/Cr、Cho/Cr和mI/Cr与对照组相比,差异无统计学意义(P＞0.05).结论:青年抑郁症患者基底节区豆状核和尾状核头部的Cho/Cr、mI/Cr增高,可能构成该病的神经生物学基础.     

颞叶癫痫~1H-MRS和DWI的变化及其相关性研究

目的 探讨~1H-MRS和DWI在反映海马硬化病理结构改变中的价值.方法 采用3.0T磁共振扫描仪对12例伴有单侧海马硬化的发作间期颞叶癫痫(TLE)患者及12例正常对照者行单体素~1H-MRS及DWI检查.比较海马N-乙酰天门冬氨酸/肌酸+胆碱[NAA/(Cr+Cho)]值,表观弥散系数(ADC)值在患侧、对侧和对照组之间的差异,分析NAA/(Cr+Cho)和ADC值之间的相关性.结果 TLE患者患侧海马NAA/(Cr+Cho)值低于对侧海马及对照组;发作间期海马ADC值高于对侧海马及对照组;患侧海马NAA/(Cr+Cho)和ADC值之间存在相关性(r=-0.79,P=0.002).结论 TLE患者患侧发作间期海马NAA/(Cr+Cho)值降低,ADC值升高,两者之间呈显著的负相关;~1H-MRS联合DWI可在活体无创反映海马硬化的病理结构改变.     

Assessment of malignancy in gliomas by 3T 1H MR spectroscopy

The purpose of this study was to assess clinical 1H MR spectroscopy (MRS) as a noninvasive method for evaluating brain tumor malignancy at 3T high-field system. Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumor (i.e., gliomas) was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantitated as a relative ratio. The variation of metabolite measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67+/-018 and 1.16+/-0.15, respectively. NAA/Cr ratio of gliomas was significantly lower than that of the normal tissues (P= .005), but Cho/Cr ratio of gliomas was significantly higher (P= .001). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas. The present study demonstrated that the neuronal degradation or loss was observed in all gliomas. Higher-grade glioma was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. Our results suggest that clinical 1H MR spectroscopy could be useful to predict tumor malignancy.     

急性一氧化碳中毒迟发脑病的磁共振波谱特征及其临床意义

目的 研究急性一氧化碳中毒迟发脑病(delayed encephalopathy following acute carbon monoxide poisoning,DEACOP)患者的质子磁共振波谱(1H magnetic resonance spectroscopy,1H MRS)特征及临床意义.方法 对38例DEACOP患者和30例正常志愿者分别进行常规核磁及质子磁共振波谱检查,对比分析DEACOP患者与正常志愿者的额叶、脑室旁、枕叶的N-乙酰天门冬氨酸(NAA)、肌酸/磷酸肌酸(Cr)、含胆碱代谢物(Cho)含量的变化,对以Cr为参照的代谢产物比值(Cho/Cr,Cho/NAA,NAA/Cr)进行比较,并分析NAA/Cr、Cho/Cr、Cho/NAA与患者简易智能状态检查量表(MMSE)和患者日常生活能力量表(ADL)的相关性.结果 获取的DEACOP组患者波谱数据显示不同部位的NAA/Cr同对照组比较降低,差异有统计学意义(P＜0.01),Cho/Cr、Cho/NAA同对照组比较增高,差异有统计学意义(P＜0.01);Cho/Cr与MMSE、ADL评分呈明显负相关,Cho/NAA与MMSE、ADL评分呈明显负相关,NAA/Cr与MMSE、ADL评分呈明显正相关.中、重度DEACOP患者NAA/Cr同轻度患者比较降低,差异有统计学意义(P＜0.05),Cho/Cr、Cho/NAA同对照组比较增高,差异有统计学意义(P＜0.05).结论 通过1H MRS检测DEACOP患者脑部病灶的代谢异常可显示神经元损伤程度,代谢物比值异常变化提示预后不佳.

Abstract：

Objective To study the characteristics of proton magnetic resonance spectroscopy (1H magnetic resonance spectroscopy, 1H MRS) in patients with delayed encephalopathy following acute carbon monoxide poisoning (DEACOP) and its significance in the early diagnosis of the disease. Methods MRI and 1H MRS were performed in 38 DEACOP patients and 30 healthy volunteers. The ratios of N-acetylaspartate ( NAA), Creatine ( Cr), Choline (Cho) peaks were measured in each volume of interest, and the correlation of Activity of Daily Living Scale (ADL) and Mini-Mental State Examination (MMSE) with NAA/Cr, Cho/Cr,Cho/NAA were analyzed. Results Compared with those of the control group, the NAA/Cr ratio in different parts decreased with very significant statistical differences ( P ＜ 0. 01 ), while Cho/Cr and Cho/NAA ratio increased also with very significant statistical difference ( P ＜ 0. 01 ). Negative correlation was found in the assessment scores between Cho/Cr and MMSE, ADL. Cho/NAA was also negatively correlated in the assessment scores with MMSE and ADL, and NAA/Cr was positively correlated in the assessment scores with MMSE and ADL. The NAA/Cr ratio in moderate and serious DEACOP patients decreased, when it was compared with that of the mild DEACOP patients, with statistical differences (P ＜ 0. 05 ). Cho/Cr and Cho/NAA ratio increased, when it was compared with that of the control group, with statistical differences ( P ＜0. 05). Conclusions 11 MRS could detect metabolic abnormalities in DEACOP patients with brain lesion.Abnormal changes in the ratio of metabolites might indicate poor prognosis.