线粒体脑肌病并高乳酸血症和卒中样发作综合征的磁共振功能影像学特征分析

目的:探讨线粒体脑肌病并高乳酸血症和卒中样发作综合征(mitochondrical encephalmyopathy withlatic acidosis and stroke-like episodes syndrome,MELAS)的磁共振功能影像学特征,以提高认识.方法:回顾性分析6例MELAS患者在磁共振功能影像学表现及疾病转归等方面的特点.结果:病变主要分布在颞顶枕皮质或皮质下白质区,以皮质受累为主.扩散加权成像(DWI),急性期病灶为高信号,表观扩散系数(ADC)为低信号.缓解期病灶DWI为等信号,ADC为高信号.急性期病变区血管增多,灌注增高.MRS乳酸波增高.MELAS病灶有迁移的特点,部分可恢复,反复发作可致局部萎缩.结论:MELAS的磁共振功能影像学表现具有一定特征性,采用多种影像学检查及肌肉活检有助于对此种综合征的正确诊断.     

可逆性后部脑病CT与MRI诊断

目的：探讨可逆性后部脑病综合征（PRES）CT与MRI表现及诊断价值。方法：回顾性分析8例PRES临床和影像学资料，7例常规行CT检查，8例常规行MRI检查，5例行弥散加权成像（DWI），其中3 例同时行钆喷替酸葡甲胺（Gd-DTPA）增强扫描。结果：CT阳性率57%，MRI阳性率100%。枕叶受累8例，小脑3例，额顶叶皮质下白质3例，脑干2例，尾状核2例，丘脑1例。在脑叶表现为脑回样异常信号，其它部位斑片样异常信号；T1WI呈略低或等信号，T2WI和FLAIR像显示明显高信号。增强扫描2例无强化，1例呈脑回样、斑片样和环样强化。DWI扫描1例呈略高信号，1例呈高信号，1例呈低信号，2例未见异常。结论：PRES的MRI表现具有特征性，MRI 应作为诊断本病的首选手段。     

脑后部可逆性脑病综合征与MELAS的磁共振特征对照研究

目的对脑后部可逆性脑病综合征(PRES)的磁共振特征进行分析并与线粒体脑肌病伴高乳酸血症和卒中样发作综合征(MELAS)进行对照,以进行诊断与鉴别诊断。方法收集21例PRES和6例MELAS患者,所有患者均行磁共振检查,回顾性分析和比较它们在MRI上的影像特征(发病部位,信号强度,功能成像特点等)。结果 21例PRES病灶主要位于皮质下白质区,13例同时累及皮质;6例MELAS病灶位于皮质及皮质下白质。DWI上,19例PRES患者病变表现为稍低信号;MELAS综合症患者,急性期病变为高信号,缓解期为等信号。2例PRES表现为局部脑血流量(CBF)减低;2例MELAS局部CBF轻度增高。结论详细的磁共振检查和分析有助于PRES和MELAS的鉴别。     

儿童异基因造血干细胞移植后可逆性后部白质脑综合征MRI表现

目的 观察儿童异基因造血干细胞移植（allo-HSCT）后可逆性后部白质脑综合征（PRES）MRI表现。方法 纳入23例allo-HSCT后PRES患儿,观察MRI所示病变累及范围、信号特点及随访变化。结果 23例顶枕叶皮质及皮质下白质均受累,21例双侧受累,2例单侧受累;7例累及额颞叶皮质及皮质下白质,3例累及深部白质,2例累及丘脑,累及胼胝体、基底节及小脑各1例。病灶于T1WI呈等或低信号,T2WI和液体衰减反转恢复（FLAIR）序列图像呈高信号,边缘模糊;14例弥散加权成像（DWI）示条片状高信号;ADC图中,皮质、皮质下及深部白质区病灶呈稍高或等信号,丘脑、基底节及小脑病灶呈稍低信号。对9例间隔10~75天（中位时间26天）复查MR,皮质及皮质下白质异常信号全部消失,4例仍可见部分丘脑及基底节病变。结论 allo-HSCT术后PRES累及范围及其MRI表现具有特征性;综合分析DWI与ADC信号特点可辅助及时诊断、积极干预,对改善患儿预后具有重要意义。     

可逆性后部白质脑病综合征CT和MRI影像学特点分析

目的:探讨可逆性后部白质脑病综合征(reversible posterior leukoencephalopathy syndrome,RPLS)CT和MRI影像学特点.方法:回顾性分析9例RPLS患者的临床及CT和MRI影像学资料.结果:MRI显示6例双侧对称性枕叶白质受累,其中4例双侧额叶顶叶白质受累,1例同时累及中脑和丘脑,1例累及尾状核头;病灶形态不规则,特征表现为皮质及皮质下白质脑回样异常信号.CT显示枕叶低密度影,其中2例广泛脑白质水肿.治疗5～20 d复查,6例病灶部分消失,1例完全消失,2例出现转化灶.结论:结合临床特点和后部脑白质损害为主的影像学表现,有助于RPLS的诊断.     

MELAS综合征MRI表现

目的:研究MELAS型线粒体脑肌病(MELAS综合征)的影像表现。材料与方法:报告一病理证实MELAS型线粒体脑肌病家族4例中的先证者的CT和MRI表现,结合文献分析该病的影像表现。结果:先证者MRI平扫见左枕、颞、顶、额叶及右枕叶大片T1WI低信号区,T2WI高信号区,DWI呈高信号,强化MRI见病灶区轻强化;MRS见NAA降低,Lac增高;同时见脑萎缩。结论:MELAS型线粒体脑肌病的MRI表现有一定的特征性。     

CT及MRI在尿毒症脑病的诊断价值

目的:探讨CT及MRI在尿毒症脑病(uremic encephalopathy,简称UE)中的诊断价值。材料与方法:回顾性分析16例尿毒症脑病的临床和影像学资料,16例患者中,男性9例,女性7例。临床表现为出现神经、精神及不自主运动等中枢神经系统方面的异常,而行颅脑CT或MRI检查,其中CT扫描3人,MRI扫描16人,DWI扫描10例,增强扫描4例。结果:CT及MRI显示病灶主要位于双侧顶枕叶皮质及皮质下白质,呈基本对称分布,脑内其它区域亦可受累。CT表现为稍低密度影;MRI表现为T1WI呈等或稍低信号,T2WI及FLAIR呈高信号。DWI表现呈较低或等信号,ADC图上呈较高信号;DWI表现呈高信号,ADC图上则呈较低信号。增强扫描均未见明显强化。结论:CT及MRI检查能够明确尿毒症脑病患者脑部病变的部位及性质,从而进一步指导治疗,预防并发症。     

MELAS综合征的主要临床及影像学特点

目的分析MELAS综合征CT、MR表现及其主要临床特点,提高对MELAS早期诊断的能力。方法回顾性分析3例MELAS综合征的临床、影像学资料。结果乳酸血症和卒中样发作为其较为特征性临床表现;病变区CT表现为低密度,MRI平扫呈等或长T1稍长T2异常信号影,急性期病灶DWI呈脑回状高信号,增强扫描无强化。肌组织活检GT染色检见红边纤维(RRF)。电镜见线粒体体积增大、数量增多。结论MELAS综合征CT、MRI具有较为特征性表现,结合肌肉活组织学检查和电镜检查有助于提高该病早期诊断率。     

30例出血性脑梗死的磁共振成像特征

[目的]探讨磁共振成像(MRI)在出血性脑梗死(HI)的临床价值.[方法]回顾性分析本院2012年2～10月收治的30例HI患者的MRI影像学资料,分析每位患者病灶的大小、形态、部位、累计范围及信号特点等.[结果]30例中发生在1个脑叶的16例(颞叶8例、额叶6例、顶叶2例),累及2个脑叶的7例(颞、顶叶5例,颞、枕叶2例),同时累及3个脑叶的5例(颞、顶、枕叶4例,额、颞、顶叶1例),其中小脑半球2例.出血在超急性期、急性期、慢性期均表现为等、长T1信号,而亚急性期表现则以短T1为主,T2为不均匀高信号,增强扫描病灶呈地图样、花边状或脑回样强化.[结论]HI磁共振成像有特征改变,可为临床诊治提供参考.     

脑灰质异位症的临床及CT、MRI诊断

目的:分析脑灰质异位症的临床资料与影像学表现特征,提高对本病的认识。方法:收集经CT、MRI检查发现的脑灰质异位症患者11例,分析脑灰质异位症的临床和影像学资料。结果:5例行CT平扫为一异常的等密度脑回样或团块状病灶,伴随病沟向脑白质延伸,窄窗宽观察更为清楚。增强扫描病灶本身无强化。6例行MR扫描,MRI可清晰显示病灶,T1WI和T2WI显示病灶呈等皮质信号,并伴随异常延伸到脑白质深处。质子密度加权像显示病灶更为清晰。灰质异位好发于顶叶,其次为颞枕叶。结论:脑灰质异位症临床与影像学均有一定的特征性,CT能诊断灰质异位症,但MRI是诊断灰质异位的首选影像学检查方法,它能清晰显示病变的部位和范围。     

妊娠期高血压脑后循环可逆性脑病综合征MRI表现 及诊断价值

目的:分析妊娠期高血压脑后循环可逆性脑病综合征(PRES)的MRI特征及诊断价值。方法:回顾性分析20例妊娠期高血压患者临床及MRI资料。所有患者治疗前行MRI平扫及DWI扫描。结果:本组伴有PRES 9例(45%),不伴有PRES 11例。MRI显示有PRES组共30个主要病灶,枕叶12个,胼胝体压部3个,顶叶半卵圆中心5个,颞叶5个,额叶3个。病灶主体位于皮质下白质、部分邻近皮质亦有受累。T_1WI等、稍低信号,T_2WI、T_2WI/flair稍高信号。DWI以等、稍高信号为主,ADC以等、稍低信号为著。T_2WI/flair发现病灶数最多,2例仅在DWI序列上显示清晰。结论:妊娠期高血压PRES MRI具有一定的特征性,DWI结合T_2WI/flair能发现更多病灶。     

左旋咪唑所致脱髓鞘脑病的CT、MRI评价(附35例报告)

目的 研究左旋咪唑致脱髓鞘脑病的CT、MRI表现特点,探讨CT、MRI的诊断价值。方法 分析35例左旋咪唑致脱髓鞘脑病的CT、MRI及临床资料。结果 本病在CT、MRI上显示为双侧脑室周围及额、顶、枕、颞叶白质区有多发病灶,CT为低密度影,MRI为长T1长T2信号,很少有占位效应。MRI的影像学诊断率明显高于CT。本病的主要临床表现为急性或亚急性起病的弥漫性脑损害的症状和体征。结论 CT、MRI能为左旋咪唑所致脱髓鞘脑病的临床诊断提供重要信息,且MRI优于CT。与有相似影像表现病变的鉴别应紧密结合临床资料,仅凭CT、MRI表现有一定局限性。     

左旋咪唑所致脑病患者的临床资料分析

目的研究左旋咪唑致脱髓鞘脑病患者的临床、CT与MRI的特点.方法分析36例左旋咪唑所致脱髓鞘脑病的临床、CT与MRI资料.结果左旋咪唑所致脱髓鞘脑病的主要临床表现为急性或亚急性起病的弥漫性脑损害,尤以早期的精神症状(77.8%)和神经障碍(91.7%)突出,皮质激素治疗效果好,36例患者的CT和MRI检查异常率分别为89%和100%,CT异常以低密度灶为主(81%),且大多数累及额、顶、颞、枕叶及侧脑室等白质区,MRI异常多为双侧脑室周围及额、顶、枕、颞叶白质区和基底节等处,呈多发、散在的长T1和长T2异常信号灶,T2加权像显示敏感,两种检查占位效应均不明显.结论该病的诊断依据其临床特点和影像学检查,CT和MRI检查对该病的鉴别诊断、治疗及预后均有较高的价值.     

小儿线粒体脑肌病的MRI表现及误诊分析

目的　探讨小儿线粒体脑肌病的 MRI表现及误诊原因。方法　搜集自 1996 - 0 1～ 2 0 0 0 - 12经 MRI检查 ,病理及实验室检查证实的小儿线粒体脑肌病 16例进行回顾性分析。结果　 16例脑内病灶均表现为多发对称性略长 T1 长T2 信号 ,其中单纯脑深部灰质受累 9例 ,大脑皮质和深部灰质同时受累 4例 ,2例灰白质同时受累 ,1例单纯白质受累。误诊 10例 ,其中临床误诊 4例 ,CT误诊 4例 ,MRI误诊 2例。结论　多样化的 MRI表现是小儿线粒体脑肌病的影像学特点 ,当小儿脑内深部灰质出现多发对称性异常信号 ,并能除外感染、梗塞、肝豆状核变性及神经中毒等其他疾病时 ,要考虑线粒体脑肌病的可能 ,影像与临床结合是减少误诊的措施     

In vivo evidence of disseminated subpial T2* signal changes in multiple sclerosis at 7 T: a surface-based analysis

Cortical subpial demyelination is frequent in multiple sclerosis (MS) and is closely associated with disease progression and poor neurological outcome. Although cortical lesions have been difficult to detect using conventional MRI, preliminary data using T2*-weighted imaging at ultra-high field 7T MRI showed improved sensitivity for detecting and categorizing different histological types of cortical MS lesions. In this study we combined high-resolution 7T MRI with a surface-based analysis technique to quantify and map subpial T2*-weighted signal changes in seventeen patients with MS. We applied a robust method to register 7T data with the reconstructed cortical surface of each individual and used a general linear model to assess in vivo an increase in subpial T2*-weighted signal in patients versus age-matched controls, and to investigate the spatial distribution of cortical subpial changes across the cortical ribbon. We also assessed the relationship between subpial T2* signal changes at 7T, Expanded Disability Status Scale (EDSS) score and white matter lesion load (WMLL). Patients with MS showed significant T2*-weighted signal increase in the frontal lobes (parsopercularis, precentral gyrus, middle and superior frontal gyrus, orbitofrontal cortex), anterior cingulate, temporal (superior, middle and inferior temporal gyri), and parietal cortices (superior and inferior parietal cortex, precuneus), but also in occipital regions of the left hemisphere. We found significant correlations between subpial T2*-weighted signal and EDSS score in the precentral gyrus (ρ=0.56, P=0.02) and between T2*-weighted signal and WMLL in the lateral orbitofrontal, superior parietal, cuneus, precentral and superior frontal regions. Our data support the presence of disseminated subpial increases in T2* signal in subjects with MS, which may reflect the diffuse subpial pathology described in neuropathology.     

Cerebral lobes in autism: early hyperplasia and abnormal age effects

Metabolic, functional, behavioral, and histologic studies suggest that the structure of the cerebrum may be abnormal in autism. In a previous cross-sectional study we found abnormal enlargement of cerebral cortex and cerebral white matter volumes in autistic 2- and 3-year-olds and abnormally slow rates of volume change across later ages. In the present study, we assessed whether these volume abnormalities are limited to particular cerebral regions or are pervasive throughout the cerebrum. We used magnetic resonance imaging (MRI) to quantify volumes of cerebral lobes (frontal, temporal, parietal, and occipital regions), using classic sulcal boundaries to define regions. We examined 38 boys with autism and 39 normal control boys between the ages of 2 and 11 years. Several regions showed signs of gray matter and white matter hyperplasia in 2- and 3-year-old patients (as much as 20% enlargement), but there appeared to be an anterior to posterior gradient in the degree of hyperplasia. The frontal lobe showed the greatest enlargement while the occipital lobe was not significantly different from normal. Gray and white matter differences were not found in the older children. By examining the relationships between regional volumes and subject age, we found that frontal, temporal, and parietal white matter volumes, as well as frontal and temporal gray matter volumes, changed at significantly slower rates in autism patients than in controls across the 2- to 11-year-age range. For example, frontal lobe white matter volume increased by about 45% from 2-4 years of age to 9-11.5 years, but by only 13% in autistic patients. Mechanisms that might account for early hyperplasia are discussed as they might relate to the regional differences in degree of abnormality. For instance, possible influences of neurotrophic factors, or of abnormal afferent activity from other affected brain regions are considered.