常规磁共振成像结合磁共振波谱在临床脑胶质瘤诊断及鉴别诊断中的应用价值

目的:分析磁共振氢质子磁共振波谱(Proton Magnetic Resonance Spectroscopy,1H-MRS)的特征与脑胶质瘤病理分级的相关性,探讨氢质子磁共振波谱及常规磁共振成像(Magnetic Resonance Imaging,MRI)联合应用在提高脑胶质瘤的临床诊断中的应用价值.方法:脑胶质瘤(经临床手术证实及病理诊断确诊)患者34例,参照国际卫生组织诊断标准,分为低级别胶质瘤组及高级别胶质瘤组.其中,低级别组16例,高级别组18例,在行常规MRI检查的同时,配合1H-MRS检查,测NAA(N-乙酰天门冬氨酸)、Cho(胆碱)、Cr(肌酸)值,在不同级别胶质瘤、同级别胶质瘤不同位置的代谢物进行综合分析.结果:在获得常规MRI图像并进行诊断后,进行氢质子磁共振波谱检测分析:在低级别胶质瘤及高级别胶质瘤患者中,Cr(肌酸)的总量变化不大,有轻度的下降;而NAA(N-乙酰天门冬氨酸)下降程度较为明显;Cho(胆碱)则明显升高.低级别胶质瘤及高级别胶质瘤患侧的肿瘤组织同对侧的正常脑组织的各种代谢物及其比值(Cho、NAA、NAA/Cho、NAA/Cr值)具有显著性差异(P＜0.05);低级别胶质瘤及高级别胶质瘤的肿瘤组织的代谢物比值NAA/Cr、NAA/Cho值差异具有显著性(P＜0.05).低级别胶质瘤及高级别胶质瘤的Cho/Cr、NAA/Cho、NAA/Cr值与脑胶质瘤的病理分级具有相关性;在各个比值中,NAA/Cr与NAA/Cho值能够较好地反映脑胶质瘤的病理分级,二者的值呈现负相关;Cho/Cr值呈正相关.结论:常规MRI联合1H-MRS在脑胶质瘤的诊断中,能够有效提高准确性,在临床评估脑胶质瘤的分级、确定范围和鉴别诊断都具有重要的指导作用.     

3.0T 1H-MRS对脑胶质瘤及脑转移瘤的鉴别诊断

目的：利用3.0T氢质子磁共振波谱对胶质瘤和转移瘤的肿瘤组织区、瘤周水肿区进行细胞代谢物水平的检测,试图找出胶质瘤和脑转移瘤的鉴别诊断的依据,以及胶质瘤高、低级别组间的差别。方法：对经病理证实的20例高级别胶质瘤组、16例低级别胶质瘤组和19例脑转移瘤组患者,先行MRI平扫及增强扫描,波谱均在增强扫描的基础上获得,使用MR点分辨波谱序列,检测肿瘤组织区、瘤周水肿组织区NAA/Cr、Cho/Cr、NAA/Cho、NAA、Cho、Cr、Lip/Lac等值,进行比较。结果：（1）高级别胶质瘤与转移瘤在肿瘤组织区NAA/Cr代谢物浓度的比值有统计学意义。（2）高、低级别胶质瘤肿瘤组织内Cho/Cr比值有统计学意义。（3）转移瘤与高、低级别胶质瘤在瘤周水肿区NAA/Cr,以及低级别胶质瘤与转移瘤Cho/Cr代谢物浓度的比值有统计学意义;高级别胶质瘤与转移瘤瘤周区NAA代谢物浓度有明显差异。（4）胶质瘤高、低级别组间在肿瘤周围区NAA峰、Cho峰及NAA/Cho Cho/Cr代谢物浓度比值有统计学意义。（5）高级别胶质瘤和转移瘤分别与低级别胶质瘤在肿瘤组织区及瘤周水肿区Lip/Lac有显著性差异（P〈0.01）。结论：利用氢质子波谱可对胶质瘤和转移瘤进行鉴别诊断;Cho/Cr及NAA/Cho比值可对胶质瘤进行分级;Lip/Lac峰的出现与肿瘤的恶性度呈正相关,但不特异。     

磁共振波谱成像结合扩散加权成像在脑胶质瘤及脑转移瘤鉴别诊断中的意义

目的:评估磁共振波谱成像(Proton Magnetic Resonance Spectroscopy,1H-MRS)联合磁共振扩散加权成像(Diffusion Weighted Imaging,DWI)在鉴别脑胶质瘤及孤立的脑转移瘤中的作用。方法:应用3.0T磁共振扫描仪,对临床手术确诊及组织病理学诊断证实的49例脑肿瘤患者(35例多形性胶质母细胞瘤,14例脑转移瘤)进行常规磁共振成像、磁共振波谱成像及磁共振扩散加权成像,并并对获得的数据进一步测量瘤内及瘤周区的代谢比、N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)值以及表观弥散系数(ADC值),分析两肿瘤组之间不同参数的统计学差异。此外,我们研究了感兴趣区域(ROI)的大小对肿瘤区域的病变扩散性能潜在影响。结果:胶质母细胞瘤瘤周N-乙酰天门冬氨酸(NAA)、肌酸(Cr),胆碱(Cho)/Cr,Cho/NAA和r CBV显著高于颅内转移瘤(P0.05);ADC值在两肿瘤组之间无显著差异(P0.05)。结论:在瘤周区1H-MRS有助于鉴别胶质母细胞瘤与单发的脑转移瘤。在瘤内扩散性的定量特性依赖ROI大小的设置。     

1H-MRS评估慢性肝病脑部代谢异常与肝硬化的相关性

目的:利用~1H-MRS研究慢性肝病脑部代谢改变,并探讨~1H-MRS评估慢性肝病脑部代谢异常与肝硬化Child-Pugh分级的相关性。方法:选取经临床确诊为慢性肝炎肝硬化患者42例(child A 19例,child B14例,child C 9例)及健康志愿者15例(对照组),行磁共振平扫及磁共振单体素~1H-MRS检查,计算相关代谢物N-乙酰天门冬氨酸(NAA)、谷氨酰胺复合物(Glx)、胆碱(Cho)、肌醇(mI)和肌酸(Cr)的峰下面积及前四项指标与Cr的比值(NAA/Cr、Glx/Cr、Cho/Cr、mI/Cr),并进行统计学分析,同时对相关代谢物的变化与肝硬化Child-Pugh分级及肝硬化Child-Pugh分级与肝性脑病的关系进行相关性分析。结果:~1HMRS分析显示与正常对照组相比,慢性肝炎肝硬化组Glx/Cr值升高,Cho/Cr与mI/Cr值降低,且差异均有统计学意义(P0.05);不同程度肝硬化病例组对比显示,Glx/Cr值均随着肝硬化程度加重而增大,且Glx/Cr值的差异在child A、child B、child C组中均有统计学意义(P0.05);肝性脑病(HE)组与非肝性脑病组脑代谢物峰下面积比值Glx/Cr、Cho/Cr、mI/Cr比较,差异有统计学意义(P0.05);Child-Pugh分级与Glx/Cr呈正相关,与Cho/Cr、mI/Cr呈负相关;随着肝硬化程度加重,肝性脑病出现概率越高,差异有统计学意义(P0.05)。结论:~1H-MRS作为一种无创性的评价手段,能够反映慢性肝硬化及肝性脑病患者存在脑代谢物浓度异常改变,可作为早期诊断肝硬化、肝性脑病及评价肝硬化、肝性脑病严重程度的一项指标,在一定程度上评估肝性脑病与肝硬化分级具有相关性。     

重度OSAS患者前额叶皮质及岛叶1H-MR波谱研究

目的:利用氢质子MRS(1H-MRS)探讨重度阻塞性呼吸睡眠暂停综合症(Severe obstructive sleep apnea syndrome,S-OSAS)患者前额叶皮质及岛叶脑代谢产物特征。方法:选择18例S-OSAS患者(S-OSAS组)和15名健康志愿者(HC组)行左侧前额叶皮质及岛叶1H-MRS检查,测量两组左侧前额叶皮质区及岛叶N-乙酰天冬氨酸/肌酸(NAA/Cr)、胆碱/肌酸(Cho/Cr)值。对患S-OSAS累计时间与前额叶皮质及岛叶NAA/Cr作直线相关分析。结果:与正常对照组相比,S-OSAS患者左侧前额叶皮质、岛叶NAA/Cr比值降低,分别为1.43±0.47、1.34±0.06,对照组分别为1.51±0.65、1.45±0.07;S-OSAS组患者左侧前额叶皮质、岛叶Cho/Cr分别为0.90±0.08、1.19±0.13,对照组分别为0.87±0.07、1.09±0.02,两组差异有统计学意义。前额叶皮质及岛叶代谢物NAA/Cr与患S-OSAS累计时间成负相关性(r值分别为-0.965、-0.955,P<0.01)。结论:1H-MRS显示S-OSAS患者前额叶皮质及岛叶病理生理变化,从该区代谢物的改变反应出S-OSAS患者执行及情感功能的异常,其NAA/Cr改变程度与患S-OSAS累计时间相关。     

重度OSAS患者前额叶皮质及岛叶1H—MR波谱研究

目的：利用氢质子MRS（IH-MRS）探讨重度阻塞性呼吸睡眠暂停综合症（Severeobstructivesleepapneasyndrome,S-OSAS）患者前额叶皮质及岛叶脑代谢产物特征。方法：选择18例S-OSAS患者（S-OSAS组）和15名健康志愿者（HC组）行左侧前额叶皮质及岛叶1H-MRS检查,测量两组左侧前额叶皮质区及岛叶N-乙酰天冬氨酸／肌酸（NAA／Cr）、胆碱／肌酸（Cho／Cr）值。对患S-OSAS累计时间与前额叶皮质及岛叶NAA／Cr作直线相关分析。结果：与正常对照组相比,S-OSAS患者左侧前额叶皮质、岛叶NAA／Cr比值降低,分别为1．43±0．47、1．34±0．06,对照组分别为1．51±0．65、1．45±0．07;S-OSAS组患者左侧前额叶皮质、岛叶Cho／Cr分别为0．90±0．08、1．195：0．13,对照组分别为0．87±0．07、1．09±0．02,两组差异有统计学意义。前额叶皮质及岛叶代谢物NAA／Cr与患S-OSAS累计时间成负相关性（r值分别为-0．965、-0．955,P〈0．01）。结论：1H-MRS显示S-OSAS患者前额叶皮质及岛叶病理生理变化,从该区代谢物的改变反应出S-OSAS患者执行及情感功能的异常,其NAA/Cr改变程度与患S-OSAS累计时间相关。     

磁共振灌注加权成像与弥散加权成像在脑胶质瘤分级诊断中的应用

目的:探讨磁共振灌注加权成像(perfusion weighted imaging,PWI)与弥散加权成像(diffusion weighted imaging,DWI)在脑胶质瘤分级诊断中的应用价值。方法:选取2012年1月-2017年6月在我院就诊并经病理证实为脑胶质瘤患者100例,其中高、低级别胶质瘤患者各44、56例。对所有患者行PWI、DWI检查,比较肿瘤不同区域表观扩散系数(apparent diffusion coefficient,ADC)、局部脑血流量(regional cerebral blood flow,rCBF),不同级别肿瘤实质区、瘤周水肿区rADC、rrCBF,根据ROC曲线分析rADC、rrCBF对不同级别胶质瘤的诊断阈值、敏感性、特异性。结果:与对侧相应正常脑实质比较,瘤周水肿区及肿瘤实质区ADC、rCBF均显著升高(P0.05);与瘤周水肿区比较,肿瘤实质区ADC、rCBF均显著升高(P0.05)。高级别肿瘤实质区rADC显著低于低级别肿瘤实质区(P0.05),rrCBF显著高于肿瘤实质区(P0.05)。高级别瘤周水肿区与低级别瘤周水肿区rADC间无显著差异(P0.05),高级别瘤周水肿区rrCBF显著高于低级别瘤周水肿区(P0.05)。在对高、低级别脑胶质瘤的分级中,rADC、rrCBF的曲线下面积(under the receiver operating characteristic curve,AUC)分别为0.957、0.978,均0.9。rADC诊断不同分级胶质瘤的敏感度是90.12%,特异度是95.26%,诊断阈值是13.12;rrCBF诊断不同分级胶质瘤的敏感度是92.31%,特异度是98.57%,诊断阈值是2.62。rADC与rrCBF诊断不同分级胶质瘤敏感度、特异度间无显著差异(P0.05)。结论:PWI、DWI能够为脑胶质瘤的分级诊断提供参考依据。     

弥散加权成像联合磁共振波谱分析在脑梗死中的应用研究

目的探讨脑梗死弥散加权成像（DWI）和磁共振波谱分析（MRS）的特点和影响因素,及二者对评估脑梗死的临床价值。方法采用Philips Achieva 1.5T双梯度超导磁共振扫描仪,对72例临床疑是脑梗死患者行常规T1WI、T2WI、FLAIR、DWI、MRS检查,在工作站上测定梗死核心区、内缘区、外缘区、周围区和镜像区的ADC值和代谢物Lac、NAA、Cr、Cho、NAA/Cr、Lac/Cr、Lac/NAA值。结果 DWI显示的梗死灶范围较常规MRI像更加准确、清晰;超急性期、急性期、亚急性期和慢性期梗死核心区的Lac/Cr值和Lac/NAA值高于对侧镜像区,ADC值和NAA/Cr值低于对侧镜像区,存在统计学差异（P〈0.05）;DWI的影响因素有b值、扩散系数、T2穿透效应和各向异性等,MRS的影响因素有磁场均匀性、压水压脂性能、体素、TE与TR、组织代谢物浓度和波谱采集链等。结论 DWI结合MRS能更加全面地评估缺血半暗带,更精确地对脑梗死进行分期和定位。     

兔实验性肝性脑病1H磁共振波谱初步研究

目的:研究兔实验性肝性脑病1H磁共振波谱(magnetic resonance spectroscopy,MRS)变化。方法:将24只兔子随机分三组:对照组,肝硬化组,肝性脑病组,各8只。肝性脑病组采用四氯化碳(CCl4)联合内毒素方法制作肝性脑病兔子模型,肝硬化组采用CCl4制作肝硬化模型。分别在第4、6、8、10、12周取肝脏病理活检,第12周测量血氨值,并进行兔子脑组织的MRS扫描。计算N-乙酰天门冬氨酸(N-acetyl asparte,NAA)、肌酸(creatine,Cr)、胆碱(choline,Cho)、肌醇(myo-inositol,mI)和谷氨酰胺复合物(glutamine and glutamate,Glx)的峰下面积,计算NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr。结果:与对照组及肝硬化组相比,肝性脑病组兔血氨上升,脑部MRS显示Glx/Cr升高,Cho/Cr降低,差异显著(P0.05)。与对照组相比,肝硬化组血氨以及MRS改变无统计学意义。结论:兔实验性肝性脑病1H磁共振波谱存在变化。     

乳铁蛋白在人脑胶质瘤中的表达及意义

目的：通过对乳铁蛋白生物学特性的研究,分析其在人脑胶质瘤中的表达及意义。方法：通过免疫组化方法测定10例非肿瘤脑组织和46例胶质瘤（其中低级别胶质瘤27例（I级和II级）和高级别胶质瘤19例（III级和Ⅳ级）中乳铁蛋白的表达情况并分析二者的相关性。用RT—PCR技术及Westem—blot方法测定非肿瘤脑组织、低级别组胶质瘤和高级别胶质瘤组乳铁蛋白的表达量并分析二者的相关性。结果：乳铁蛋白在非肿瘤脑组织及不同级别胶质瘤中的表达情况不同,其在低级别胶质瘤中有表达,略低于非肿瘤脑组织;而在高级别胶质瘤中表达显著减少或者表达不明显,明显低于低级别胶质瘤和非肿瘤脑组织（免疫组化、RT．PCR及Western．Blot的P值分别为P=0．001、P=0．003、P=0．004）。结论：乳铁蛋白在非肿瘤脑组织和不同级别胶质瘤中的表达有差异,提示乳铁蛋白参与了人脑胶质瘤发生与发展的过程。高级别胶质瘤的高度恶性和高侵袭性可能与乳铁蛋白表达的下调从而丧失对肿瘤细胞的抑制作用相关。     

In vitro study of astrocytic tumour metabolism by proton magnetic resonance spectroscopy

In vivo magnetic resonance spectroscopy (MRS) studies of glial brain tumours reported that higher grade of astrocytoma is associated with increased level of choline-containing compounds (Cho) and decreased levels of N-acetylaspartate (NAA) and creatine and phosphocreatine (Cr). In this work, we studied the metabolism of glioma tumours by in vitro proton magnetic resonance spectroscopy (1H-MRS). 1H-MR spectra were recorded in vitro from perchloric acid extracts of astrocytoma (WHO II) and glioblastoma multiforme (WHO IV) samples. We observed differences between astrocytoma and glioblastoma multiforme in the levels of Cho, alanine, lactate, NAA, and glutamate/glutamine. In astrocytoma samples, we found higher MR signal of NAA and lower signal of Cho and alanine. MR spectra of glioblastoma samples reported significantly higher levels of lactate and glutamate/glutamine. In contrast, levels of Cr were the same in both tumour types. We also determined NAA/Cr and Cho/Cr ratios in the tumour samples. The NAA/Cr ratio was higher in astrocytomas than in glioblastomas multiforme. Conversely, the Cho/Cr ratio was higher in glioblastoma multiforme. The results indicate that MRS is a promising method for distinguishing pathologies in human brain and for pre-surgical grading of brain tumours.     

Convex-Envelope Based Automated Quantitative Approach to Multi-Voxel 1H-MRS Applied to Brain Tumor Analysis

Background

Magnetic Resonance Spectroscopy (MRS) can measure in vivo brain tissue metabolism that exhibits unique biochemical characteristics in brain tumors. For clinical application, an efficient and versatile quantification method of MRS would be an important tool for medical research, particularly for exploring the scientific problem of tumor monitoring. The objective of our study is to propose an automated MRS quantitative approach and assess the feasibility of this approach for glioma grading, prognosis and boundary detection.

Methods

An automated quantitative approach based on a convex envelope (AQoCE) is proposed in this paper, including preprocessing, convex-envelope based baseline fitting, bias correction, sectional baseline removal, and peak detection, in a total of 5 steps. Some metabolic ratios acquired by this quantification are selected for statistical analysis. An independent sample t-test and the Kruskal-Wallis test are used for distinguishing low-grade gliomas (LGG) and high-grade gliomas (HGG) and for detecting the tumor, peritumoral and contralateral areas, respectively. Seventy-eight cases of pre-operative brain gliomas with pathological reports are included in this study.

Results

Cho/NAA, Cho/Cr and Lip-Lac/Cr (LL/Cr) calculated by AQoCE in the tumor area differ significantly between LGG and HGG, with p≤0.005. Using logistic regression combining Cho/NAA, Cho/Cr and LL/Cr to generate a ROC curve, AQoCE achieves a sensitivity of 92.9%, a specificity of 72.2%, and an area under ROC curve (AUC) of 0.860. Moreover, both Cho/NAA and Cho/Cr in the AQoCE approach show a significant difference (p≤0.019) between tumoral, peritumoral, and contralateral areas. The comparison between the results of AQoCE and Siemens MRS processing software are also discussed in this paper.

Conclusions

The AQoCE approach is an automated method of residual water removal and metabolite quantification. It can be applied to multi-voxel ¹H-MRS for evaluating brain glioma grading and demonstrating characteristics of brain glioma metabolism. It can also detect infiltration in the peritumoral area. Under the limited clinical data used, AQoCE is significantly more versatile and efficient compared to the reference approach of Siemens.     

磁共振波谱分析与帕金森病患者Hoehn&Yahr分级的相关性研究

目的:探讨磁共振波谱分析(MRS)与帕金森病(PD)HoehnYahr分级之间的相关性。方法:选择2016年9月-2017年8月我院收治的60例PD患者为研究对象,根据HoehnYahr分级将患者分为早期PD组32例、中期PD组18例、晚期PD组10例,并选择同时期在门诊进行健康体检的20例志愿者作为对照组。对各组研究对象的双侧基底节、双侧额叶、双侧丘脑区进行MRS,并分析PD患者HoehnYahr分级与MRS的关系。结果:晚期PD组双侧基底节、双侧额叶、双侧丘脑区NAA/Cr、NAA/Cho、Cho/Cr比值均低于中期PD组、早期PD组、对照组,且中期PD组低于早期PD组、对照组,早期PD组低于对照组,差异有统计学意义(P0.05)。通过Spearman相关性分析显示,MRS检测出PD患者NAA/Cr、NAA/Cho、Cho/Cr比值与HoehnYahr分级间呈负相关性(P0.05)。结论:MRS与PD患者的HoehnYahr分级具有负相关性,并且可通过MRS预测患者疾病的严重程度,以对其进行相应的治疗以及预后评估。     

Differences between Spinocerebellar Ataxias and Multiple System Atrophy-Cerebellar Type on Proton Magnetic Resonance Spectroscopy

Purpose

A broad spectrum of diseases can manifest cerebellar ataxia. In this study, we investigated whether proton magnetic resonance spectroscopy (MRS) may help differentiate spinocerebellar ataxias (SCA) from multiple systemic atrophy- cerebellar type (MSA-C).

Material and Methods

This prospective study recruited 156 patients with ataxia, including spinocerebellar ataxia (SCA) types 1, 2, 3, 6 and 17 (N = 94) and MSA-C (N = 62), and 44 healthy controls. Single voxel proton MRS in the cerebellar hemispheres and vermis were measured. The differences were evaluated using nonparametric statistic tests.

Results

When compared with healthy controls, the cerebellar and vermis NAA/Cr and NAA/Cho were lower in all patients(p<0.002). The Cho/Cr was lower in SCA2 and MSA-C (p<0.0005). The NAA/Cr and Cho/Cr were lower in MSA-C or SCA2 comparing with SCA3 or SCA6. The MRS features of SCA1 were in between (p<0.018). The cerebellar NAA/Cho was lower in SCA2 than SCA1, SCA3 or SCA6 (p<0.04). The cerebellar NAA/Cho in MSA-C was lower than SCA3 (p<0.0005). In the early stages of diseases (SARA score<10), significant lower NAA/Cr and NAA/Cho in SCA2, SCA3, SCA6 or MSA-C were observed comparing with healthy controls (p<0.017). The Cho/Cr was lower in MSA-C or SCA2 (p<0.0005). Patients with MSA-C and SCA2 had lower NAA/Cr and Cho/Cr than SCA3 or SCA6 (p<0.016).

Conclusion

By using MRS, significantly lower NAA/Cr, Cho/Cr and NAA/Cho in the cerebellar hemispheres and vermis were found in patients with ataxia (SCAs and MSA-C). Rapid neuronal degeneration and impairment of membrane activities were observed more often in patients with MSA-C than those with SCA, even in early stages. MRS could also help distinguish between SCA2 and other subtypes of SCAs. MRS ratios may be of use as biomarkers in early stages of disease and should be further assessed in a longitudinal study.     

Proton magnetic resonance spectroscopy in diagnostics of epilepsy

Present paper presents proton MRS investigation results. The investigation was carried out with Magnetom Vision device. Twenty-five patients in the age of 20-44 years suffering with generalization epileptic fits validated by EEG (no visible changes on MRT) were examined. In all cases independently on the localization of the changes, decreasing of NAA and increasing of Cho were recorded. At one side temporal lobe injury recorded by EEG at the damaged part decreasing of NAA/Cr and NAA/Cho + Cr ratios were registered. Patients with bilateral changes registered by EEG showed non-equal changes of metabolite concentration on both sides. Examination of patients suffering with distinct symptoms of temple epileptics has shown ipsilaterality decrease of NAA and Cr concentration. But on the injured side NAA/Cr ratio decrease was more distinct. In general, the laterality was recorded in 14 patients out of 22 with pathological changes registered by proton MRS and in 10 patients out of 14 the above mentioned changes corresponds to the side of the fit initiation. In the patients with bilaterality changes NAA/Cr ratio asymmetry was recorded in all cases, but the most distinctly in the medium part of the temple lobe. Comparison of data recorded in 8 patients suffering with one side fit complex has shown significant asymmetry of metabolites which was observed in ipsilaterality and contra laterality NAA ratio obtained in hippocampal areas. Difference in NAA ratio obtained between left and right sides are 19-25%. Left-right ratio of other metabolites corresponded to that ratio in the control group and was symmetrical.     

Detecting neuronal dysfunction of hand motor cortex in ALS: A MRSI study

Background: Although hand motor cortex (HMC) has been constantly used for identification of primary motor cortex in magnetic resonance spectroscopy (MRS) studies of amyotrophic lateral sclerosis (ALS), neurochemical profiles of HMC have never been assessed independently. As HMC has a constant location and the clinic–anatomic correlation between hand motor function and HMC has been established, we hypothesize that HMC may serve as a promising region of interest in diagnosing ALS.

Patients and methods: Fourteen ALS patients and 14 age- and gender-matched healthy controls (HC) were recruited in this study. An optimized magnetic resonance spectroscopic imaging (MRSI) method was developed and for each subject bilateral HMC areas were scanned separately (two-dimensional multi-voxel MRSI, voxel size 0.56?cm³). N-acetyl aspartate (NAA)–creatine (Cr) ratio was measured from HMC and the adjacent postcentral gyrus.

Results: Compared with HC, NAA/Cr ratios from HMC and the postcentral gyrus were significantly reduced in ALS. However, in each group the difference of NAA/Cr ratios between HMC and the postcentral gyrus was not significant. Limb predominance of HMC was not found in either ALS or HC. In ALS, there was a significant difference in NAA/Cr ratio between the most affected HMC and the less affected HMC. A positive relationship between NAA/Cr ratio of HMC and the severity of hand strength (assessed by finger tapping speed) was demonstrated.

Conclusion: Neuronal dysfunction of HMC can differentiate ALS patients from HC when represented as reduced NAA/Cr ratio. Postcentral gyrus could not serve as normal internal reference tissue in diagnosing ALS. Asymmetrical NAA/Cr ratios from bilateral HMC may serve as a promising diagnostic biomarker of ALS at the individual level.