VBM分析在颞叶癫痫患者脑结构MRI检测中的应用

【目的】基于像素的形态学测量（VBM ）法分析颞叶癫痫患者脑区灰质密度和体积的差异,探讨VBM对常规M RI未发现病灶的颞叶癫痫患者的检测准确性。【方法】选择本院收治的30例常规M RI未发现病灶的颞叶癫痫患者（颞叶癫痫组）,其中男13例,女17例;选择同期本院体检健康者30例（对照组）,其中男16例,女14例。采用磁化预备快速梯度回波序列进行高分辨率全脑结构像扫描两组研究对象脑部,通过VBM分析其全脑灰质体积及密度变化。【结果】①颞叶癫痫患者组的左侧枕叶、楔叶,右侧小脑山顶脑区的灰质密度较对照组降低,差异有显著性意义;双侧壳核、外侧苍白球、左侧颞下回、右侧额下回脑区的灰质密度较对照组升高,差异有显著性意义;②颞叶癫痫患者组双侧岛叶,右侧中央前回、颞上回、楔叶、楔前叶、枕中回、缘上回,左侧颞中回、角回、舌回、颞横回、中央后回、中央旁小叶、海马旁回、梭状回的脑灰质体积较正常对照组降低,差异有显著性;未发现灰质体积升高的脑区。【结论】颞叶癫痫患者不仅颞叶灰质存在异常,而且颞叶外脑区也存在广泛的灰质异常,对于常规M RI未发现病灶的颞叶癫痫患者,进行VBM 分析可发现广泛的脑结构异常。     

颞叶癫痫儿童灰质异常脑区与神经心理学测验的关系及意义

[目的]评估儿童颞叶癫痫（ TLE）临床表现和神经心理学测验成绩与局部脑萎缩的相关性.[方法]症状性TLE患儿14例（海马萎缩所致中颞叶癫痫 9例,颞叶新皮质损伤所致TLE 5例）,健康对照儿童14名;中颞叶癫痫（ MTLE）成人及其对照各9例.所有入组对象进行脑MRI获取T1结构像,用像素为基础的形态测定法分析图像.所有儿童进行综合神经心理学测验.[结果]TLE患儿同侧海马和海马外周区灰质体积显著减小,灰质体积减小与神经心理学测验成绩显著相关（P〈0.05）.单侧海马萎缩的MTLE患儿中,癫痫发作区域同侧的海马灰质体积显著减小,同侧扣带和对侧额中回皮质萎缩,皮质萎缩程度及范围较同类成人患者小.[结论]与成人MTLE患者相似,儿童MTLE与海马和海马外周的细胞减少有关;儿童TLE灰质萎缩的程度和范围较成人患者小,仅限于额叶区;中颞叶和额叶区灰质体积的减小与神经心理学测验成绩显著相关;TLE患儿的认知或行为障碍是神经网络损伤的结果.     

基于体素形态学和表面形态计量学MRI观察肌萎缩侧索硬化患者大脑结构改变

目的 探讨肌萎缩侧索硬化（ALS）患者大脑形态结构的改变,以期寻找有效的早期诊断影像学标记。方法 采集27例临床确诊ALS患者（ALS组）和27名健康志愿者（对照组）的3D-T1W脑结构像,分别以基于体素形态学（VBM）和基于表面形态计量学（SBM）方法对全脑结构进行分析。将2种算法得到的ALS组有显著差异脑区的灰质体积与临床修订版ALS功能评分量表（ALSFRS-R）评分分别进行相关分析。结果 VBM分析结果显示,与对照组比较,ALS组双侧中央前回、左侧背侧丘脑、右侧辅助运动区、左侧中央沟盖、双侧中央后回等运动相关脑区灰质体积显著减小,双侧额叶、颞叶、枕叶及海马旁回等运动区以外的脑区灰质体积亦缩小。SBM分析结果显示,与对照组比较,ALS组右侧BA4a、BA4p区灰质体积和皮层厚度降低。ALS组右侧BA4a区灰质体积与ALSFRS-R评分呈正相关（r=0.418,P=0.038）。结论 ALS患者大脑运动区和运动区域以外脑结构均有所改变,BA4a区的灰质体积及皮层厚度有望作为生物学标记物,用于监测疾病病程进展。     

MorphoBox自动分割皮层下灰质核团

目的 观察MorphoBox自动分割皮层下灰质核团(丘脑、壳核、尾状核、苍白球和海马)的价值。方法 收集40例颞叶癫痫(TLE)患者,按癫痫灶所在侧别将其分为左侧TLE(LTLE)组和右侧TLE(RTLE)组;另纳入22名健康人作为健康对照(HC组)。比较MorphoBox与传统Freesurfer基于MRI所测丘脑、壳核、尾状核、苍白球及海马体积的差异,评估MorphoBox的效能。结果 MorphoBox与Freesurfer所测双侧壳核、双侧尾状核、右侧苍白球及双侧海马体积差异均有统计学意义(P均<0.05)。MorphoBox所测LTLE和RTLE组两侧壳核、尾状核及海马体积差异均有统计学意义(P均<0.05);Freesurfer所测RTLE组两侧丘脑体积和LTLE与RTLE组两侧壳核、尾状核、苍白球及海马体积差异均有统计学意义(P均<0.05)。除HC组双侧海马外,MorphoBox与Freesurfer所测其余基底核团体积结果均相关(0.471≤r≤0.850);除HC组右侧苍白球及双侧海马外,二者所测其余基底核团体积结果均具有一致性(0.392≤ICC...     

颞叶癫痫内侧颞叶结构体积变化及与临床因素相关性研究

目的：探讨颞叶癫痫（TLE）海马、杏仁核及内嗅皮层体积变化及与临床的相关性。方法：采用MRI对117例TLE患者的海马、杏仁核及内嗅皮层体积进行测量并进行临床相关性研究。结果：有侧别优势的TLE患侧海马体积较对侧小，其中海马硬化组患侧和对侧内嗅皮层体积也存在差异，而杏仁核体积均未见明显差异；海马及杏仁核体积变化与发作频率、起病年龄的早晚、病程长短、高热惊厥之间未见明显相关性，海马硬化组内嗅皮层体积减少程度与复杂部分性发作频率存在相关性。结论：内侧颞叶结构对颞叶癫痫相关的损伤敏感性存在差别。     

基于自动分割技术联合基于体素的形态学观察帕金森病脑灰质结构

目的 探讨基于自动分割技术联合基于体素的形态学(VBM)观察帕金森病(PD)患者全脑灰质异常区域及分布特征的应用价值。方法 基于自动分割技术,应用FIRST工具对29例PD患者(PD组)及30名健康人(对照组)的T1图像皮层下灰质结构精确分割,对比两组各灰质结构体积。并应用VBM方法对两组脑灰质图像进行比较。结果 两组右侧壳核皮层下灰质体积差异有统计学意义(t=10.201,P<0.05)。与对照组比较,PD组脑灰质体积(右侧初级运动皮层,双侧额叶、边缘叶、部分左侧小脑后叶、右侧小脑前叶、右侧小脑后叶、右侧颞叶、顶叶、壳核及左侧枕叶)广泛减少,部分左侧小脑后叶体积增加,两侧半球脑体积缺失不对称(右侧大于左侧)。结论 通过FIRST工具可精确分割并直接计算皮层下灰质结构体积,应用VBM技术可定量分析脑结构形态学异常;二者结合可较全面地表现PD脑灰质体积广泛减少的形态学特点。     

结合型局灶性脑皮层发育不良的MRI表现

目的 探讨结合型局灶性脑皮层发育不良(FCDⅢ型)的MRI影像表现。方法 回顾性分析经临床、手术及病理证实的158例符合FCDⅢ型的MRI影像资料,总结FCDⅢ型的异常影像表现特点。结果 158例FCDⅢ型病灶中,有147例位于颞叶(比例约为93.0%),120例FCDⅢa型的FCD病灶均为前颞叶脑组织。113例FCDⅢ型中FCD病灶影像异常,阳性率约71.5%,其中FCDⅢa、FCDⅢb型、FCDⅢc型、FCDⅢd型影像阳性率分别为81.7%、47.8%、50%、11.1%。FCD病灶异常影像表现为病灶区灰白质分界稍模糊(83.2%),皮层T_2FLAIR序列信号轻度增高(69.9%),皮层轻度增厚(49.6%),皮层T2WI序列信号略有增高(20.4%),局部脑叶萎缩(14.2%)等影像特点。结论 FCDⅢ型中FCD病灶影像异常表现轻微,常为多个轻度异常影像相互存在,发生部位以颞叶为主,FCDⅢa型发病率最高,故发生于颞叶的海马硬化、肿瘤、血管畸形等病变时,需要排除存在FCDⅢ型可能,尤其是在发现海马硬化时,要注意对前颞叶轻微异常影像表现提高警惕,对提高癫痫外科术前及预后评估有重要意义。     

颞叶癫痫患者rs-fMRI功能连接及其与记忆功能关系的研究

目的:分析颞叶癫痫患者静息态磁共振(rest-f MRI)功能连接及其与记忆功能之间的关系,探讨其脑功能连接的异常及其对记忆障碍诊治的应用价值。方法:对16例颞叶癫痫患者(癫痫组)和与之相匹配的16例健康对照者(对照组)进行静息态脑功能成像和记忆功能测评,比较2组间的脑区差异,分析与记忆功能相关的脑区。结果:癫痫组与对照组比较,海马与全脑功能连接增高的脑区有:左侧旁中央小叶、左侧中央前回、左侧中央后回、左侧前运动皮质和辅助运动区、左侧内侧额叶等;减低的脑区有:右侧小脑、左侧颞上回等。癫痫组海马与全脑功能连接与记忆商呈正相关的脑区有:双侧前扣带回、双侧楔前叶/后扣带回等;呈负相关的脑区有:左侧额下回、左侧中央后回等。结论:左侧旁中央小叶、左侧中央前回、左侧中央后回、左侧前运动皮质和辅助运动区、左侧内侧额叶等脑区可能构成颞叶癫痫患者的癫痫网络,在癫痫发生和发展过程中起重要作用;右侧小脑、左侧颞上回等脑区的功能异常可能与颞叶癫痫患者认知功能损伤有关。双侧前扣带回、双侧楔前叶/后扣带回、左侧额下回、左侧中央后回等脑区与海马之间的功能连接与记忆相关,其对记忆功能具有潜在临床预测价值。     

儿童颞叶癫痫的临床特点及MRS的定位诊断价值分析

目的:探讨儿童颞叶癫痫(TLE)的临床特点以及磁共振波谱分析(MRS)对儿童TLE病灶定位的诊断价值。方法:共选择2017年5月~2019年4月40例临床确诊为儿童TLE的临床资料作为研究(实验组),对患儿的病灶及海马组织标本进行病理检查,分析临床病理及发作特点。并选择同期40例健康志愿者作为对照(对照组),两组均行常规磁共振成像(MRI)和MRS,分析实验组患者、对侧及对照组的海马NAA/Cr、NAA/Cho和NAA/(Cho+Cr)比值。结果:病理结果显示,排在前3位的为FCDⅢb、低级别肿瘤、局灶性皮层发育不良。40例儿童TLE临床共发作70次,临床发作症状最多的为意识改变、口部自动症。常规MRI,健康志愿者无异常;儿童TLE双侧海马大小不对称,患侧海马体积缩小、颞角扩大共16例,患侧FLAIR序列海马信号增高共9例。MRS,TLE患侧的NAA/Cr、NAA/Cho、NAA/(Cho+Cr)值明显小于TLE对侧、健康者左侧、健康者右侧,差异有统计学意义(P<0.05);TLE对侧、健康者左侧、健康者右侧两两间比较无明显差异,无统计学意义(P﹥0.05)。结论:儿童TLE的诊断应依据临床发作特点及MRS综合分析,MRS能够无创并定量反映儿童TLE海马生化代谢异常,在TLE的术前定位中具有重要的诊断价值。     

颞叶内侧癫痫全脑灰质基于体素的MRI形态分析

目的应用MRI基于体素的形态学测量方法（VBM）,分析颞叶内侧癫痫患者全脑灰质结构的改变。方法对23例颞叶内侧癫痫患者（其中右侧病变11例,左侧病变12例）,13例年龄性别与之匹配的健康志愿者行全脑扫描,应用磁化准备快速梯度回波成像序列获取三维结构图像。数据分析采用以SPM99软件包为基础的全自动VBM技术进行处理。结果与健康对照组比较,颞叶内侧癫痫患者显示了患侧和对侧海马,以及丘脑、扣带回等边缘系统结构灰质密度的减少。额叶及小脑皮层等结构也显示弥漫灰质密度的减少。结论VBM法操作简单,不但可检测颞叶内侧癫痫海马结构的异常,还可显示海马结构以外弥漫脑灰质结构的异常。     

儿童颞叶中内侧硬化所致颞叶癫痫的MRI研究

目的 对儿童颢叶癫痫进行前瞻性MRI研究分析。探讨儿童颢叶癫痫的MRI表现特征。方法 对127例临床和脑电图检查诊断为颢叶癫痫的儿童进行MRI多序列成像．分析研究颞叶的形态结构、信号并判断海马有无萎缩性改变。结果 127例颢叶癫痫患儿中，9例(7．1％)海马有萎缩性改变，且在T2加权成像和液体率减恢复(F1AIR)成像上呈高信号。9例中，6例伴有海马受累同侧颞叶信号异常；3例伴有同侧颞叶皮层结构不良；1例伴有同侧颞叶萎缩。结论 颞叶中内侧硬化是儿童颢叶癫痫的一个相对少见原因，受累侧海马MRI表现为萎缩和信号异常，同时常伴海马外颞叶结构受累。     

Composite voxel-based analysis of volume and T2 relaxometry in temporal lobe epilepsy

Voxel-based analyses of tissue characteristics such as volume and T2 are usually carried out in isolation. However, as the images are analysed in a common voxel-based framework, it is possible to directly assess the spatial relationships of abnormalities detected by each technique. We utilize this approach in well-characterized patients with unilateral temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS). TLE is associated with potentially widespread volume and T2 signal abnormalities in MRI images but the relationship between these two aspects of tissue abnormality is not well understood. Here we use a novel approach of combined univariate and multivariate voxel-wise analysis to investigate the spatial relationship of these abnormalities. We studied 19 TLE patients and compared them to 115 control subjects. Grey matter (GM) and white matter (WM) volume changes were assessed with voxel-based morphometry (VBM), and changes in T2 relaxation times were evaluated with voxel-based relaxometry (VBR). The volume and T2 changes obtained using the combined univariate approach were found in an extensive area, prominently in the ipsilateral hippocampus and amygdala (overlap of GM-VBM and VBR), and in the remaining temporal lobe (overlap of WM-VBR and VBR). Other cortical and subcortical areas showed isolated volume or T2 changes. The multivariate analysis based on the Hotelling T(2) statistic, indicated a similar pattern of distributed changes across the brain but with a greater degree of statistical significance in certain areas. The composite analyses appear to identify a network of affected areas not as easily appreciated by the individual analysis of volume or T2 changes.     

Voxel-by-voxel comparison of automatically segmented cerebral gray matter--A rater-independent comparison of structural MRI in patients with epilepsy.

Quantitative evaluation of MRI in patients with epilepsy can give more information than qualitative assessment. Previously developed volume-of-interest-based methods identified subtle widespread structural changes in the neocortex beyond the visualized lesions in patients with malformations of cortical development (MCD) and hippocampal sclerosis (HS) and also in MRI-negative patients with juvenile myoclonic epilepsy (JME). This study evaluates a voxel-based automated analysis of structural MRI in epilepsy. After fully automated segmentation of cerebral gray matter from structural T1-weighted, high-resolution MRI scans, we applied the automated and objective technique of statistical parametric mapping (SPM) to the analysis of gray matter of 35 control subjects, 10 patients with partial seizures and MCD, 10 patients with left temporal lobe epilepsy (TLE) and HS, 10 patients with left TLE and normal MR quantitation of the hippocampus, and 20 patients with JME. At a corrected threshold of P < 0.05, significant abnormalities were found in 3/35 controls; in all 10 patients with MCD, 6 of whom had additional lesions beyond the margins of the visualized abnormalities; in 2/10 TLE patients with HS; in 2/10 MRI-negative TLE; and in 4/20 JME patients. Group comparisons between control subjects and HS patients identified the affected left temporal lobe with an increase in gray matter in the posterior temporal lobe, but did not identify hippocampal atrophy. The group of MRI-negative TLE patients showed no abnormalities compared with control subjects. Group comparison between control subjects and JME patients identified a mesial frontal increase in gray matter. The SPM-based voxel-by-voxel comparison of gray matter distribution identified MCD and abnormalities beyond the visualized lesion in individual MCD patients. The method did not reliably identify HS in individual patients or identify abnormalities in individual MRI-negative patients with TLE or JME in a proportion larger than the chance findings in the control group. Using group comparisons, structural abnormalities in the neocortical gray matter of patients with TLE and HS were lateralized to the affected temporal lobe. In patients with JME as a group, an increase in gray matter was localized to the mesial frontal area, corroborating earlier quantitative MRI findings.     

Tractography of the parahippocampal gyrus and material specific memory impairment in unilateral temporal lobe epilepsy

INTRODUCTION: Temporal lobe epilepsy (TLE) is associated with disrupted memory function. The structural changes underlying this memory impairment have not been demonstrated previously with tractography. METHODS: We performed a tractography analysis of diffusion magnetic resonance imaging scans in 18 patients with unilateral TLE undergoing presurgical evaluation, and in 10 healthy controls. A seed region in the anterior parahippocampal gyrus was selected from which to trace the white matter connections of the medial temporal lobe. A correlation analysis was carried out between volume and mean fractional anisotropy (FA) of the connections, and pre-operative material specific memory performance. RESULTS: There was no significant difference between the left and right sided connections in controls. In the left TLE patients, the connected regions ipsilateral to the epileptogenic region were found to be significantly reduced in volume and mean FA compared with the contralateral region, and left-sided connections in control subjects. Significant correlations were found in left TLE patients between left and right FA, and verbal and non-verbal memory respectively. CONCLUSION: Tractography demonstrated the alteration of white matter pathways that may underlie impaired memory function in TLE. A detailed knowledge of the integrity of these connections may be useful in predicting memory decline in chronic temporal lobe epilepsy.     

磁源性影像在海马硬化致癫灶定位中的应用

目的：探讨磁源性影像对由海马硬化引起的颞叶癫痫术前致癫灶定位价值。方法：对16例海马硬化的病例术前实行脑磁图检查,并应用磁源性影像技术对致癫灶进行定位。结果：术后随访,按照南京军区总医院的评估标准：满意14例（87.5%）;显著改善1例（6.25%）;疗效差1例（6.25%）;总有效率93%。磁源性影像定位与视频脑电图的定位完全符合率为62.5%。结论：磁源性影像可以明确海马硬化患者癫痫源异常放电位置,可以用于术前致癫灶的定位。     

Whole-brain voxel-based statistical analysis of gray matter and white matter in temporal lobe epilepsy

Volumetric MRI studies based on manual labeling of selected anatomical structures have provided in vivo evidence that brain abnormalities associated with temporal lobe epilepsy (TLE) extend beyond the hippocampus. Voxel-based morphometry (VBM) is a fully automated image analysis technique allowing identification of regional differences in gray matter (GM) and white matter (WM) between groups of subjects without a prior region of interest. The purpose of this study was to determine whole-brain GM and WM changes in TLE and to investigate the relationship between these abnormalities and clinical parameters. We studied 85 patients with pharmacologically intractable TLE and unilateral hippocampal atrophy and 47 age- and sex-matched healthy control subjects. The seizure focus was right sided in 40 patients and left sided in 45. Student's t test statistical maps of differences between patients' and controls' GM and WM concentrations were obtained using a general linear model. A further regression against duration of epilepsy, age of onset, presence of febrile convulsions, and secondary generalized seizures was performed with the TLE population. Voxel-based morphometry revealed that GM pathology in TLE extends beyond the hippocampus involving other limbic areas such as the cingulum and the thalamus, as well as extralimbic areas, particularly the frontal lobe. White matter reduction was found only ipsilateral to the seizure focus, including the temporopolar, entorhinal, and perirhinal areas. This pattern of structural changes is suggestive of disconnection involving preferentially frontolimbic pathways in patients with pharmacologically intractable TLE.     

Voxel-based morphometric comparison of hippocampal and extrahippocampal abnormalities in patients with left and right hippocampal atrophy

We used voxel-based morphometry (VBM), an automatic whole-brain MR image analysis technique, to investigate gray matter abnormalities in patients with temporal lobe epilepsy (TLE), in whom hippocampal atrophy (HA) was demonstrated by application of the Cavalieri method of modern design stereology. VBM results (P < 0.05, corrected) indicated preferential gray matter concentration (GMC) reduction in anterior hippocampus in patients with left HA and posterior hippocampus in patients with right HA. GMC reduction was also found in right dorsal prefrontal cortex in left and right HA patients. Prefrontal atrophy may be due to epileptiform excitotoxic discharges from the reciprocally connected pathological hippocampus, and may be the underlying biological cause for executive dysfunction in patients with TLE. GMC excess in ipsilateral parahippocampal, cerebellar, and pericallosal regions was common to both left and right HA groups relative to controls, and is hypothesized to reflect diminished gray-white matter demarcation, underlying white matter atrophy, or structural displacement due to cerebrospinal fluid expansion. However, bilateral temporal lobe GMC excess was observed in left HA patients, while ipsilateral temporal lobe GMC excess was observed in right HA patients. This work demonstrates methodological consistency between automated VBM and manual stereological analysis of the hippocampus in group comparisons, indicates widespread extrahippocampal gray matter abnormalities in unilateral HA, and suggests that there may be inherent differences in the effect of TLE on temporal lobe structures depending on the side of HA.     

颞叶癫痫的1H MRSI和MRI体积测量研究

目的评价质子磁共振波谱成像(1H-MRSI)和MRI体积测量对颞叶癫痫(TLE) 的定侧诊断价值.方法对13例单侧TLE和13例对照者行MRI和1H-MRSI扫描,测量颞叶氮-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)的浓度比率及海马结构体积.结果 TLE组8例海马结构萎缩,患侧海马结构NAA/Cr及NAA/(Cr Cho) 显著小于对侧及对照组(前者F=5.187,P=0.012;后者F=6.731,P=0.004);患侧颞叶外侧皮层的NAA/Cr显著小于对侧(t=-2.82, P=0.015).海马体积测量定侧敏感性为61.5%; 1H-MRSI定侧敏感性为84.6%.结论 1H-MRSI可发现颞叶广泛的代谢异常,增加定侧诊断敏感性.     

Mapping limbic network organization in temporal lobe epilepsy using morphometric correlations: insights on the relation between mesiotemporal connectivity and cortical atrophy

Temporal lobe epilepsy (TLE) is considered primarily a limbic disorder. Our purpose was to map limbic network organization in TLE and to statistically relate it to neocortical atrophy. We performed MRI-based cortical thickness analysis in 110 TLE patients (including 68 patients with hippocampal atrophy and 42 patients with normal hippocampal volume) and 46 healthy controls. Limbic connectivity was statistically inferred by correlating mean thickness of the entorhinal cortex (EC) with thickness at each vertex across the entire neocortex. The EC was chosen as seed region since it is the link between the neocortex and the hippocampal formation. Patients showed cortical thinning mainly in temporal and fronto-central neocortices, with a prevalence of atrophy in up to 35%. In controls, EC networks corresponded closely to known anatomical connections. In TLE the pattern of correlations was similar to controls, suggesting that pathological processes in the EC affect the same networks that co-vary with the EC in the healthy brain. Nevertheless, we found decreases in correlations mainly in the temporal lobe and increases mainly in orbitofrontal cortices. Although our analysis indicated alterations in the temporo-limbic network in TLE, there was no association between mesiotemporal connectivity and atrophy across the entire cortical surface. This divergence underlines the complexity of the pathophysiological mechanisms leading to neocortical atrophy in TLE.