多体素^1H MRS测定正常脑组织不同区域的代谢物分布

目的: 测定正常人脑组织不同部位代谢物浓度、计算其比值.材料和方法: 用多体素磁共振质子波谱PRESS序列测定100例正常脑组织的额叶、颞叶、顶叶、枕叶、基底节区和小脑代谢物浓度,观察NAA、Cho、Cr的波峰特点,计算和分析NAA/Cr、Cho/Cr、NAA/Cho的比值.结果: 正常脑实质的1H波谱Levene方差分析显示额叶、颞叶、顶叶、枕叶、基底节区和小脑的NAA/Cr(P<0.000)和NAA/Cho(P=0.001)有显著差异,Cho/Cr在上述各部位的浓度无显著差异(P=0.068).进一步用Bonferroni方差分析比较各组间显著差异性显示小脑NAA/Cr低于额叶、顶叶、枕叶的NAA/Cr(P值分别<0.05,<0.01,<0.05),小脑NAA/Cho低于顶叶、枕叶的NAA/Cho(P均<0.01),而额叶、颞叶、顶叶、枕叶、基底节区之间NAA/Cr、NAA/Cho无显著差异.结论: 多体素1H MRS可以测定NAA/Cr、Cho/Cr、NAA/Cho浓度比值,不同解剖部位代谢物浓度不尽相同,为颅脑代谢异常提供参考标准.     

小儿正常小脑半球组织~1H-MRS研究

目的:测定和计算0～7岁小儿正常小脑半球组织代谢物比值,并观察各比值随年龄变化规律。方法:应用多体素2D1H-MRS点分辨波谱(PRESS)序列测定70例0～7岁小儿正常小脑半球组织的双侧灰质及白质区代谢物浓度,按年龄分为0-1岁,1-2岁,2-3岁,3-5岁,5-7岁五组,计算和分析NAA/Cr、Cho/Cr、NAA/Cho的比值。结果:正常小脑灰质区在各年龄组间NAA/Cho(P=0.0143)和NAA/Cr(P=0.0050);白质区的NAA/Cho和NAA/Cr均P<0.001;灰质和白质区的Cho/Cr(P=0.1195,P>0.05);灰质和白质区NAA/Cho值与年龄呈正相关(P<0.001,P<0.0001);NAA/Cr值与年龄呈正相关(P=0.0004,P<0.0001);灰质区Cho/Cr与年龄呈负相关(P=0.038),白质区与年龄呈负相关(P=0.568>0.05)。结论:0～7岁小儿正常小脑半球灰、白质的代谢物比值在不同年龄组会不同,灰质和白质区NAA/Cho、NAA/Cr值随年龄增长逐渐升高,而灰质区Cho/Cr值逐渐减小,白质区无明显变化,临床上应用MRS要考虑其年龄和部位的因素。     

正常成年人颞叶扣带回后部MR波谱与年龄的相关性研究

目的 采用氢质子磁共振波谱(1H-MRS)分析探讨正常成年人年龄对颞叶扣带回后部脑组织代谢物浓度的影响.方法 选出79例无精神神经等疾病经颅脑MRI检查阴性的正常人分成4组:<45岁(16例),45～54岁(22例),55～64岁(29例),＞64岁(12例);测量双侧颞叶扣带回后部脑组织内N-乙酰基天门冬氨酸(NAA)、肌酸(Cr)、胆碱复合物(Cho)、肌醇(mI)的浓度及NAA/ Cr、Cho/Cr、mI/Cr比值.组间比较采用方差分析,年龄与检测指标间的相关分析采用简单相关和偏相关分析法.结果 颞叶扣带回后部NAA/Cr比值在4个年龄组间差异有统计学意义(P<0.001);组间两两比较表明,<45岁组与其他年龄组间差异有统计学意义(P<0.05),<45岁组颞叶扣带回后部NAA/Cr最高.NAA、Cr、Cho、mI的浓度及Cho/Cr、mI/Cr比值在各年龄组差异无统计学意义.相关性分析显示NAA浓度及NAA/ Cr比值与年龄呈负相关(偏相关系数分别为r=-0.4304,P=0.0001;r=0.4895,P<0.0001),随年龄增大NAA浓度及NAA/Cr比值减低. mI/Cr比值与年龄呈正相关(偏相关系数r=0.3400,P=0.0030),随年龄增大mI/Cr比值增高.结论 正常成年人颞叶扣带回后部神经元数量与活性随年龄增大减低,髓鞘退变及胶质增生随年龄增大而增高.     

短暂性脑缺血发作的质子磁共振波谱研究

目的:探讨短暂性脑缺血发作(TIA)的质子磁共振波谱(1H-MRS)改变及其临床应用价值.方法:分别对25例TIA患者和25例健康志愿者(正常对照组)行1H-MRS,测量两侧大脑半球半卵圆中心代谢物包括氮乙酰天门冬氨酸(NAA)、胆碱(Cho)和肌酸(Cr)的波峰下面积,计算NAA/Cho、NAA/Cr和Cho/Cr.对TIA患者病变侧与对侧正常脑组织及正常对照组之间各代谢物比值的差异进行统计学分析.结果:TIA患者病变侧半卵圆中心的NAA/Cho(1.48±0.23)、NAA/Cr(1.23±0.17)低于对侧(1.68±0.24,1.79±0.21)及正常对照组(1.66±0.24,1.78±0.17),差异有极显著性意义(P＜0.01);其Cho/Cr(1.18±0.19)高于对侧(1.05±0.16)及正常对照组(1.04±0.12),差异有显著性意义(P＜0.05).结论:1H-MRS能够早期发现TIA患者的脑代谢异常,对临床诊断和治疗具有重要价值.     

健康成人脑代射物浓度以及比值的1HMRS研究

目的探讨脑内代谢物及其比值与年龄变化的关系.材料和方法正常健康志愿者51名,无神经系统疾病,分为中、青年组30名(年龄18～45岁)和老年组21名(年龄62～78岁).用GE 1.5T Signa超导磁共振扫描仪,采用定点分辨波谱序列(PRESS)对额叶、颞叶、枕叶以及海马区的NAA、tCr、Cho和MI测定并计算NAA/Cr、Cho/Cr、MI/Cr的比值.结果中青年组和老年组之间上述四个部位的脑内代谢物的浓度以及其比值无明显差异.结论脑内额叶、颞叶、枕叶和海马区的NAA、Cr、Cho和MI浓度及其比值与年龄无关.     

阻塞性睡眠呼吸暂停综合征的质子磁共振波谱研究

目的:探讨阻塞性睡眠呼吸暂停综合征(OSAS)的质子磁共振波谱(1H-MRS)改变及其临床应用价值.方法:分别对33例OSAS患者和20例健康志愿者行1H-MRS,经多导睡眠仪监测将患者分为轻度OSAS(16例)和中重度OSAS(17例),分别测量脑灰质和脑白质的代谢物包括氮-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)和乳酸(Lac)的波峰下面积,计算NAA/Cho、NAA/Cr、Cho/Cr,对组间代谢物比值的差异进行统计学分析.结果:中重度OSAS患者白质区NAA/Cho(1.56±0.21)低于轻度OSAS患者(1.88±0.23)及正常对照组(1.89±0.25),差异有显著性意义(P<0.01),NAA/Cr轻度降低,Cho/Cr轻度升高,但与轻度OSAS患者和正常对照组比较,无统计学意义(P>0.05).轻度OSAS患者灰、白质NAA/Cho、NAA/Cr、Cho/Cr 与正常对照组之间差异均无显著性意义(P>0.05).结论:1H-MRS能够早期发现OSAS患者的脑代谢异常,对临床诊断和治疗具有重要价值.     

MR动脉血质子自旋标记与波谱成像在颈内动脉系统狭窄或闭塞的应用研究

目的 探讨MR动脉血质子自旋标记(ASL)与氢质子磁共振波谱成像(1H-MRS)在颈动脉系统狭窄或闭塞的应用价值. 资料与方法 28例单侧颈内动脉(ICA)/大脑中动脉(MCA)重度狭窄或闭塞患者行ASL 和1H-MRS检查.对ASL后处理的相对脑血流量(CBF) 图进行定性和定量分析;对1H-MRS测量病变侧和对侧脑组织的氮-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)的波峰下面积,比较两侧各代谢物峰下面积比值(NAA/Cho、NAA/Cr、Cho/Cr)的差异,并观察是否出现乳酸(Lac)峰. 结果 28例CBF图显示18例病变侧灌注较对侧降低,10例未见明显异常;1H-MRS显示病变侧的NAA/Cho、NAA/Cr低于对侧,差异有统计学意义(P<0.01),Cho/Cr高于对侧,差异有统计学意义(P<0.01),3例于病变侧检测到Lac峰. 结论 ASL 能够早期发现颈动脉系统狭窄或闭塞患者的CBF改变,1H-MRS能够显示缺血脑组织的代谢异常.     

胼胝体变性的扩散加权成像和多体素氢质子波谱分析

目的 探讨扩散加权成像(DWI)和多体素氢质子波谱(1H-MRS)在急性和亚急性胼胝体变性(MBD)中的应用价值. 资料与方法 5例长期酗酒男性MBD 患者均经DWI检查,其中急性型3例经1H-MRS检查,测量DWI不同信号病灶的ADC值,多体素1H-MRS采集胼胝体病灶的胆碱复合物(Cho)、氮-乙酰天门冬胺酸(NAA)、肌酸(Cr)等波峰,计算Cho/Cr、NAA/Cr及Cho/NAA的比值. 结果 大部分病灶在DWI上表现为高和稍高信号,根据液体衰减翻转恢复序列(FLAIR)、DWI、ADC图上病灶信号的不同分为3组,不同病灶区的ADC值表现为不同程度升高或降低.1H-MRS示胼胝体病灶的Cho/Cr升高,NAA/Cr不同程度下降,1例探测到倒置的乳酸(Lac)峰,所有胼胝体病灶的Cho/NAA均明显升高,比值在2.03～2.53之间.结论 DWI和1H-MRS分别可以提供MBD所致脑组织微观结构的改变和局部代谢物变化方面的信息,对于MBD的诊断具有重要价值.     

~1H-MRS在脑胶质瘤诊断及分级中的应用

目的:分析脑胶质瘤的氢质子磁共振波谱(proton magnetic resonance spectroscopy,1H-MRS)表现及其临床意义;探讨脑胶质瘤的1H-MRS特点与其病理级别相关性。方法:搜集经临床手术、病理证实的脑胶质瘤38例,按照WHO分级(2000)标准分成两组:低级别脑胶质瘤组、高级别脑胶质瘤组。所有患者在术前行1H-MRS检查,均在MR非增强成像的基础上获得。使用GE Signa1.5T超导磁共振扫描仪,多体素扫描,点分辨选择波谱法,检测不同区域代谢物变化。结果:脑胶质瘤的1H-MRS表现:肌酸(Cr)无明显变化;N-乙酰天门冬氨酸(NAA)下降,胆碱(Cho)增高,变化的程度由肿瘤级别高低决定;低级别、高级别脑胶质瘤的肿瘤组织分别和对侧正常脑组织的NAA/Cr、Cho/Cr、NAA/Cho比值存在显著性差异(P<0.01);低级别脑胶质瘤和高级别脑胶质瘤的肿瘤组织的NAA/Cr、Cho/Cr、NAA/Cho比值有统计学意义(P<0.05),脑胶质瘤的NAA/Cho、Cho/Cr、NAA/Cr比值与病理级别相关。结论:1H-MRS与MRI相结合能提高脑胶质瘤术前诊断的准确性。1H-MRS可评价脑胶质瘤的分级,反映脑胶质瘤代谢特性以及肿瘤生长潜能。     

3T MRI上鼠脑多体素1H-MRS成像因素及其代谢物比值研究

目的:探讨影响鼠脑多体素1H-MRS的成像因素及在3T MRI上正常鼠脑代谢物值.材料和方法:40只正常雄性SD大鼠,体重200～250g.利用3T MRI扫描机、大鼠专用线圈对SD大鼠尾状核行二维多体素1H-MRS检查,采用点分辨波谱(PRESS)序列,TR/TE=1000ms/35ms,FOV 60mm,层厚4mm,NEX 1;利用波谱后处理软件FuncTool重建SD大鼠正常尾状核Cho/Cr、Cho/NAA、NAA/Cr的比值.结果:40只行多体素1H-MRS检查的正常SD大鼠,其尾状核Cho/Cr的平均值为0.97±0.20、Cho/NAA为0.79±0.33、NAA/Cr为1.34±0.34.在多体素1H-MRS检查中,关键要选择合适的体素位置,并对匀场进行优化,同时要恰如其分的放置饱和带.结论:在3T MRI上进行鼠脑多体素1H-MRS切实可行;通过测定正常鼠脑的代谢物比值,为以后的科研工作提供有价值的参考值.     

多体素1H - MRS在脑肿瘤强化周围区域中的临床应用

目的探讨多体素1H磁共振波谱(1H-MRS)在颅脑肿瘤强化周围区的代谢物改变特点及其鉴别诊断意义。方法脑肿瘤患者35例,多体素1H-MRS采集NAA、Cho、Cr、Lac、L ip、m I和A la峰,分别计算星形细胞瘤、转移瘤、脑膜瘤的肿瘤强化区、强化周围区和正常参照区域的代谢物浓度,计算不同脑肿瘤、同种脑肿瘤不同区域及高、低级胶质瘤各代谢物比值平均值,比较统计学差异,记录Lac、L ip、m I和A la是否出现。结果肿瘤强化区NAA/Cho、NAA/Cr和Cho/Cr平均值与正常参照区比较均有显著性差异(P<0.05);共出现17例Lac峰、7例L ip峰、6例A la峰和6例m I峰;强化周围区,三者的NAA/Cho、NAA/Cr、NAA/nCr、Cho/NAA值具显著性差异;良、恶性胶质瘤间,NAA/Cho、NAA/nCr、Cho/Cr和Cho/nCho值具有统计学差异(P<0.05)。结论多体素1H-MRS对肿瘤强化周围区域的评价,有助于星形细胞瘤与脑转移瘤、脑膜瘤的鉴别诊断及浸润范围的划定。     

MR image segmentation and tissue metabolite contrast in 1H spectroscopic imaging of normal and aging brain.

The impact of image segmentation on 0.84-ml nominal voxel volume proton spectroscopic imaging in normal brain and in age-related cortical atrophy was investigated. Segmentation improved the gray matter-white matter (GM-WM) contrast for N-acetyl aspartate (NAA)/creatine (Cr) and choline (Cho)/Cr in normal brain, and for NAA/Cho and NAA/Cr in atrophic brain. NAA(GM/WM) (approximately 0.7), Cho(GM/WM) (approximately 0.8), and Cr(GM/WM) (approximately 1.3) in normal brain obtained with segmentation agreed with values obtained with quantitative magnetic resonance spectroscopy. Age-related cortical atrophy led to decreased cortical GM NAA/Cho and NAA/Cr; no changes were evident in WM or in NAA(GM/WM), Cho(GM/WM), or Cr(GM/WM). GM/WM metabolite analysis may be of limited use in conditions in which parallel metabolite changes occur in WM and GM.     

3.0T ~1H-MRS在脑内高级别星形细胞瘤及单发转移瘤鉴别诊断中的价值

目的:探讨多体素氢质子磁共振波谱(1 H-MRS)对脑高级别星形细胞瘤、单发脑转移瘤的鉴别诊断价值。方法:收集经手术、活检病理证实的颅脑肿瘤患者37例,其中高级别星形细胞瘤(Ⅲ~Ⅳ级)17例(间变性星形细胞瘤5例,胶质母细胞瘤12例),脑单发转移瘤20例。37例行颅脑常规MRI检查及多体素1 H-MRS分析,分析肿瘤实质强化区、强化边缘区、对侧相应正常区域脑组织的生化代谢物及其比值,并进行对照。结果:1脑高级别星形细胞瘤、脑转移瘤1 H-MRS与对侧相应正常区域对比均表现为Cho峰升高,NAA、Cr峰下降。12例胶质母细胞瘤中,显示Lip峰者11例。20例脑转移瘤中,11例见Lac峰升高,9例Lip峰升高。2高级别星形细胞瘤肿瘤实体区的Cho/NAA明显高于脑转移瘤(P0.05);高级别星形细胞瘤瘤周水肿的Cho/Cr、Cho/NAA明显高于脑转移瘤(P0.05)。结论:3.0T1 H-MRS分析对高级别星形细胞瘤、脑单发转移瘤的诊断和鉴别诊断有重要价值,可作为一种非损伤性的鉴别手段;肿瘤瘤周水肿带的波谱更有利于胶质瘤与转移瘤的鉴别。     

Evaluation of cerebral glioma grade by using normal side creatine as an internal reference in multi-voxel 1H-MR spectroscopy

PURPOSE Our purpose was to evaluate cerebral glioma grade by using normal side creatine (Cr) as an internal reference in multi-voxel 1H-MR spectroscopy. MATERIALS AND METHODS We examined 25 adult patients with glial brain tumors. Ratios of maximum Cho/Cr (normal) (max- Cho/Cr(n)) and minimum NAA/Cr(normal) (min-NAA/ Cr(n)) were determined using Cr levels in the normal parenchyma. In addition, maximum Cho/Cr (max- Cho/Cr) and minimum NAA/Cr (min-NAA/Cr) were calculated from spectrum in the tumor areas. Tumors were graded according to metabolite ratios and the findings were compared to histopathological test results. The sensitivity, specificity, positive and negative predictive values of metabolite ratios were determined. RESULTS The ratio of max-Cho/Cr(n) was lower than that of max-Cho/Cr in the high-grade group (P = 0.001). Min-NAA/Cr(n), min-NAA/Cr, and max-Cho/Cr ratios demonstrated statistically significant differences between high-grade (n = 19) and low-grade tumors (n = 6). The min-NAA/Cr and min-NAA/Cr(n) ratios were inversely correlated with tumor grade (P = 0.027 and P = 0.009, respectively). CONCLUSION Use of normal side Cr as an internal reference provides a more objective evaluation for brain tumor grading. Our data showed that Cr tended to be low in the high-grade tumors. In addition to conventional metabolite ratios, the Min-NAA/Cr(n) ratio might be useful in brain tumor grading. Combined use of metabolite ratios might be helpful in grading brain tumors in cases without significantly increased Cho/Cr ratios.     

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.     

Proton MR spectroscopy in neonates with perinatal cerebral hypoxic-ischemic injury: metabolite peak-area ratios, relaxation times, and absolute concentrations

BACKGROUND: Results from cerebral proton (1)H-MR spectroscopy studies of neonates with perinatal hypoxic-ischemic injury have generally been presented as metabolite peak-area ratios, which are T1- and T2-weighted, rather than absolute metabolite concentrations. We hypothesized that compared with (1)H-MR spectroscopy peak-area ratios, calculation of absolute metabolite concentrations and relaxation times measured within the first 4 days after birth (1) would improve prognostic accuracy and (2) enhance the understanding of underlying neurochemical changes in neonates with neonatal encephalopathy. METHODS: Seventeen term infants with neonatal encephalopathy and 10 healthy controls were studied at 2.4T at 1 (1-3) and 2 (2-4) (median [interquartile range]) days after birth, respectively. Infants with neonatal encephalopathy were classified into 2 outcome groups (normal/mild and severe/fatal), according to neurodevelopmental assessments at 1 year. The MR spectroscopy peak-area ratios, relaxation times, absolute concentrations, and concentration ratios of lactate (Lac), creatine plus phosphocreatine (Cr), N-acetylaspartate (NAA), and choline-containing compounds (Cho) from a voxel centered on the thalami were analyzed according to outcome group. RESULTS: Comparing the severe/fatal group with the controls (significance assumed with P < 0.05), we found that Lac/NAA, Lac/Cho, and Lac/Cr peak-area ratios increased and NAA/Cr and NAA/Cho decreased; Lac, NAA, and Cr T2s were increased; [Lac] was increased and [Cho], [Cr], and [NAA] decreased; and among the concentration ratios, only [Lac]/[NAA] was increased. Comparison of the normal/mild group with controls revealed no differences in peak-area ratios, relaxation times, or concentration ratios but decreased [NAA], [Cho], and [Cr] were observed in the infants with normal/mild outcome. Comparison of the normal/mild and severe/fatal groups showed increased Lac/NAA and Lac/Cho and decreased NAA/Cr and NAA/Cho peak-area ratios, reduced [NAA], and increased Lac T2 in the infants with the worse outcome. CONCLUSIONS: Metabolite concentrations, in particular [NAA], enhance the prognostic accuracy of cerebral (1)H-MR spectroscopy-[NAA] was the only measurable to discriminate among all (control, normal/mild, and severe/fatal outcome) groups. However, peak-area ratios are more useful prognostic indicators than concentration ratios because they depend on metabolite concentrations and T2s, both of which are pathologically modulated. Concentration ratios depend only on the concentrations of the constituent metabolites. Increased Cr T2 may provide an indirect marker of impaired cellular energetics, and similarly, NAA T2 may constitute an index of exclusively neuronal energy status. Our recommendation is to collect data that enable calculation of brain metabolite concentrations. However, if time constraints make this impossible, metabolite peak-area ratios provide the next best method of assigning early prognosis in neonatal encephalopathy.     

鼻咽癌放疗后放射性脑病的1H-MR波谱研究

目的　探讨鼻咽癌放疗后放射性脑病的磁共振氢波谱 (1H MRS)表现 ,了解N 乙酰天门冬氨酸 (NAA)、肌酸 (Cr)和胆碱 (Cho)这 3种物质的代谢规律 ,为放射性脑病的早期诊断提供方法。方法　对照组 10例健康志愿者 ,病例组 2 1例病理诊断为鼻咽癌并进行根治性放疗后经症状及影像学诊断为放射性脑病的病人 ,用化学位移成像法 (CSI)行1H MRS检查。观察各像素中NAA、Cr和Cho的含量、代谢图及它们之间比例。结果　放射性脑病MRI可见病灶中的液化坏死区 3种物质含量基本为零 ,代谢图中无信号 ;可见病灶中非液化坏死区NAA轻度升高 ,Cr和Cho明显降低或为零 ,NAA代谢图呈高信号 ,Cr和Cho低信号 ;可见病灶周边存在 1个区域性的NAA降低、Cr和Cho升高 ,NAA/Cr和NAA/Cho <1,代谢图中信号区分不明显 ;远离可见病灶的区域NAA、Cr和Cho含量及比例正常。结论　1H MRS发现物质代谢变化是有规律的 ,变化的区域大于MRI中可见病变区 ,为早期诊断提供了可能性。     

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.     

Reproducibility of short echo time proton magnetic resonance spectroscopy using point-resolved spatially localized spectroscopy sequence in normal human brains.

The reproducibility of short echo time proton MR spectroscopy (1H-MRS) in normal human brains was examined. Thirteen healthy volunteers were studied, and each underwent three MRS examinations. Second and third measurements were done on the same day, about two months after the first measurement, and interday and intraday reproducibility were evaluated. MRS was performed with proton brain examination/single voxel (PROBE/SV) and point-resolved spatially localized spectroscopy (PRESS) (repetition time = 2000 ms, echo time = 30 ms). Five metabolite ratios were computed; N-acetyl-aspartate (NAA)/creatine (Cr), choline (Cho)/Cr, myo-inositol (mI)/Cr, NAA/(NAA + Cr + Cho), and NAA/Cho. Their normal range and reproducibility were measured. For each metabolite ratio, there was no significant difference between interday difference and intraday difference, suggesting that the interval of two months has minimal effect on MRS measurements. MRS may be utilized for the observation of central nervous system diseases.     

二维化学位移成像检测帕金森病基底神经节代谢物浓度的应用

目的利用二维化学位移成像（2D CSI）检测帕金森病（PD）的基底神经节代谢物浓度。探讨PD的基底神经节代谢物浓度是否变化。评估2D CSI技术检测PD的价值。资料与方法符合临床诊断标准的PD患者26例。从健康志愿者中抽取与PD组年龄、性别相匹配的26名健康者作为正常对照组。采用2D CSI技术检测所有人组对象的双侧豆状核、尾状核的代谢物浓度，包括氮-乙酰天门冬氨酸／肌酸复合物（NAA／Cr），氮-乙酰天门冬氨酸／N碱复合物（NAA／Cho）以及Cho／Cr比值。比较PD组和正常对照组的基底神经节相对应核团的代谢物浓度之间的差异。结果PD组双侧豆状核的NAA／Cho和右尾状核的NAA／Cr、左侧尾状核的Cho／Cr比值明显低于正常对照组（P＜0．05）。左侧豆状核Cho／Cr比值明显高于正常对照组（P＜0．05）。结论PD患者的基底神经节代谢物浓度与正常人有差异。2D CSI作为一种可用于检测基底神经节代谢物浓度的无创伤性的方法，将成为检测正常脑的生理性和病变脑的病理性代谢物浓度的变化，尤其是神经元变性性疾病的一种重要手段。