儿童线粒体脑肌病的脑部MRI表现与诊断

目的探讨儿童线粒体脑肌病的脑部MRI表现及其诊断价值。方法搜集1996年1月至2002年12月经病理与实验室检查证实的16例儿童线粒体脑肌病及其脑部MRI表现，并进行回顾性分析。结果16例患儿脑MRI均有多发对称性片状略长T1和长T2异常信号，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6例，单纯白质受累l例。临床主要表现为进行性智力减退(12例)和肌力减退(10例)。骨骼肌活检病理检查可见破碎样红纤维及异常线粒体。结论进行性智力和肌力减退是儿童线粒体脑肌病最常见的临床表现；脑深部灰质多发对称性斑片状异常信号是儿童线粒体脑肌病脑部MRI的主要表现；脑MRI是诊断儿童线粒体脑肌病的重要手段，但儿童线粒体脑肌病的确诊有赖于肌肉活检和基因检查。     

胚胎发育不良性神经上皮瘤的MRI表现与病理对照分析

目的:分析6例胚胎发育不良性神经上皮瘤(dysembryoplastic neuroepithelial tumors,DNT)的MRI表现和病理所见,探讨其MRI表现特征与病理间的关系。方法:回顾性分析6例经手术病理证实的DNT的MRI资料和病理所见,观察MRI信号改变与病理所见的关系。结果:典型的DNT位于皮层或主要位于皮层区,肿瘤以囊性成分为主,病灶在T1WI为低信号,T2WI为高信号,其ADC值增高,FLAIR序列上病灶边缘和分隔为高信号改变,增强扫描病灶实质结节或分隔可见轻度强化。瘤周无水肿,三角征和瘤内分隔为其影像学表现特征。与之病理对照所见DNT肿瘤细胞弥漫分布、密度不高、胞浆较空、存在黏液湖及肿瘤内富含薄璧分枝状血管是形成MRI所见的组织学基础。结论:DNT的MRI所见具有特征性,反映了其组织病理学改变特征,在病理诊断困难的情况下,结合临床和影像学表现,可以对DNT做出正确的诊断。     

瓦斯爆炸有毒气体中毒后脑部MRI表现及其与创伤后应激障碍的相关性研究

目的 动态观察瓦斯爆炸伤后脑部MRI表现及其变化规律,探讨MRI表现与创伤后应激障碍(PTSD)的相关性.方法 选取瓦斯爆炸后幸存者49例(A组)、爆炸当天未下井矿工40名(B组)、地面工作的矿区人员40名(C组).对A组于瓦斯爆炸后1至3 d内进行首次脑部MR检查,并进行多次复查(2、3、6个月及1年),观察病变的影像改变及其信号演变;测量3组海马、苍白球的T2信号强度值,并进行方差分析;对病变组海马、苍白球T2信号强度值及海马ADC值与PTSD的关系进行t检验.结果 A组首次MRI表现:海马(33例)、苍白球(12例)、皮层(10例)及中脑(2例)呈稍长T1长T2异常信号;2个月复查:海马异常信号消失25例,遗留稍长T2信号8例;苍白球3例异常信号消失,余9例苍白球病变范围均缩小呈软化灶改变;受累皮层2例演变为软化灶,余病变恢复正常;脑干呈软化灶改变.A组与B组、C组海马及苍白球的T2信号强度值之间差异均有统计学意义(P值均<0.01),B组与C组海马及苍白球的T2信号强度值之间差异无统计学意义(P值均>0.05);A组PTSD与非PTSD患者首次检查时左侧海马T2信号强度值分别为455±37、462±53,右侧为458±36、460±43;2个月时左侧海马T2信号强度值分别为438±29、424±37,右侧分别为442±31、430±32,差异均无统计学意义(t值分别为0.499、0.193、1.512、1.298,P值均>0.05).A组PTSD与非PTSD患者首次检查时左侧苍白球T2信号强度值分别为361±35、366±63,右侧为363+41、375±62;2个月时左侧苍白球T2信号强度值分别为341±24、337±39,右侧分别为340±26、332±35,差异亦无统计学意义(t值分别为0.350、0.826、0.503、0.907,P值均>0.05).A组PTSD与非PTSD患者首次检查时左侧海马ADC值分别为(8.1±1.1)×10-4、(8.1±0.9)×10-4mm2/s,右侧为(8.2±1.0)×10-4、(8.2±0.8)×10-4mm2/s,差异均无统计学意义(t值分别为0.016、0.081,P值均>0.05);2个月时左侧海马ADC值分别为(8.8±0.7)×10-4、(9.0±1.0)×10-4mm2/s,差异无统计学意义(t=0.333,P>0.05),右侧分别为(8.5±0.9)×10-4、(9.3±1.1)×10-4mm2/s,差异具有统计学意义(t=7.407,P<0.05).结论 海马及苍白球是瓦斯爆炸极易受损的脑区,PTSD的发生可能与右侧海马的损害相关,而与苍白球的损害无关.     

In vitro delineation of human brain-stem anatomy using a small resonator: correlation with macroscopic and histological findings

Our purpose was to investigate the potential of an experimental animal coil using a commercial MRI unit to delineate the anatomical structure of the human brain stem. Three formaldehyde-fixed brain-stem specimens were examined by MRI and sectioned perpendicular to their longitudinal axis. The images were compared with gross anatomy and myelin-stained histological sections. Fibre tracts and nuclei which were not evident on examination of the unstained specimen were readily identified by MRI. Due to its inherent grey/white matter contrast, MRI with a highresolution coil delineates anatomical structures in a way comparable to the myelin-stained histological sections. However, pigmented structures, readily visible on examination of the unstained specimen were discernible on neither MRI nor on myelin-stained sections. The excellent anatomical detail and grey/white matter contrast provided by these images could make MRI a useful adjunct to the pathologist investigating brain disease.     

儿童脑型肺吸虫病活动期的MRI表现

目的 研究早期活动性脑型肺吸虫病的MRI表现,提高对该病的早期诊断及治疗。方法 经酶联免疫吸附试验（ELISA）阳性的4例患儿,均经MRI常规SE序列扫描,1例行MR血管造影。回顾分析其MRI表现特点。结果 4例MRI均发现多发、不规则、大小不等的出血灶,部分围绕与出血灶不相称的水肿信号,即较小的出血灶伴有较大的水肿带,病灶随机分布,并呈聚集或迁移状,1例可见“隧道”征,早期表现为自中脑大脑脚上行至右侧丘脑的条状出血信号,出血吸收后形成长T1的隧道样表现。结论 MRI可清晰显示肺吸虫迁移引起的脑实质多发出血、炎性病变、水肿及特征性隧道形成,对肺吸虫脑病的活动期诊断具有重要价值。     

Measurement of the apparent diffusion coefficient in paediatric mitochondrial encephalopathy cases and a comparison of parenchymal changes associated with the disease using follow-up diffusion coefficient measurements

Objectives

To reveal the contribution of MRI and diffusion-weighted imaging (DWI) to the diagnosis of mitochondrial encephalopathy (ME) and to evaluate the parenchymal changes associated with this disease in the involved parenchymal areas using the apparent diffusion coefficient (ADC) parameter.

Methods

Ten patients who had undergone MRI and DWI analysis with a pre-diagnosis of neurometabolic disease, and who were subsequently diagnosed with ME in laboratory and/or genetic studies, were included in our study. ADC values were compared with a control group composed of 20 patients of similar age with normal brains. Evaluations involved measurements made in 20 different areas determined on the ADC map. The dominance or contribution of ADC coefficient measurements to the conventional sequences was compared with the controls.

Results

In the first examination, an increase in both diffusion and ADC values was detected in six cases and diffusion restriction and a decrease in ADC values in three patients. While an increase in both diffusion and ADC values was demonstrated in four cases, there was diffusion restriction and a decrease in ADC values in three cases in the control examinations.

Conclusions

DWI provides information that complements conventional MRI sequences in the diagnosis of ME.     

Neuroradiologic findings in children with mitochondrial disorders.

PURPOSEWe report the neuroradiologic findings in 25 children with various mitochondrial diseases.METHODSTwenty-two children with a mitochondrial disorder had MR imaging of the brain and three children had CT studies. In all cases, the diagnosis was based on examination of muscle morphology, analysis of oxygen consumption and respiratory chain enzyme activity in isolated muscle mitochondria, and analysis of rearrangements of the mitochondrial DNA.RESULTSFifteen patients were found to have the classical syndromes of mitochondrial diseases. Four children had Kearns-Sayre syndrome, but only one had the typical neuroradiologic findings of basal ganglia and brain stem lesions, T2 hyperintensity of the cerebral white matter, and cerebellar atrophy; the others had nonspecific or normal findings. Eight patients had Leigh syndrome, and all showed changes in the putamina. Involvement of the caudate nuclei, globus pallidi, thalami, and brain stem was common, and diffuse supratentorial white matter T2 hyperintensity was seen in two of these patients. Three patients had mitochondrial encephalopathy with lactic acidosis and strokelike episodes (MELAS), with infarctlike lesions that did not correspond to the vascular territories. Ten children with complex I or IV deficiencies and abnormal muscle morphology had nonspecific imaging findings, such as atrophy and abnormal or delayed myelination. One patient with combined complex I and IV deficiency had extensive white matter changes. None of the patients with clinical encephalopathy had normal findings.CONCLUSIONMR imaging is helpful in the diagnosis of the classical mitochondrial diseases; however, nonspecific findings are common.     

胆管囊腺癌的MRI表现与病理的对照分析

目的 探讨MRI诊断胆管囊腺癌（BCAC）的价值。方法 回顾性分析5例经手术病理证实的BCAC患者的MRI表现，并与病理所见对照。结果 4例单发，1例多发。5例均为囊实性肿物，2例单房、3例多房，囊内可见多个大小不等的壁结节及厚薄不均的间隔。液性部分呈均匀的长T1、长T2信号，实性部分呈稍长T1、稍长T2信号。注射钆喷替酸葡甲胺（Gd—DTPA）后，囊性部分无强化，实性部分动脉期轻度强化、门静脉期及延迟期呈中度至明显强化。MRI表现与病理所见对应良好。术前4例诊断为囊腺瘤或囊腺癌，1例诊断为胆管癌。结论 MRI能显示BCAC的特征性表现，可以做到术前正确诊断。     

脑胶质肉瘤的MRI表现

目的：评价MRI对脑胶质肉瘤的诊断价值。方法：经病理证实的脑胶质肉瘤6例，回顾分析其MRI表现。结果：病灶基本上表现为长T1、长T2信号，边界清楚，多数形态不规则，伴有囊变和坏死，可伴瘤内出血，生长具有侵袭性；少数为结节状。周围服组织水肿，占位效应明显。增强扫描：6例均明显强化，4例呈不规则环状强化，2例呈结节状强化；2例直接侵犯邻近脑叶，2例发现脑内转移灶。结论：脑胶质肉瘤通常发生于额、顶叶，MRI能够清楚地显示病变，但信号改变易与多形胶质母细胞瘤、恶性胶质瘤、转移瘤等相混淆。确诊仍依赖于组织病理学诊断。     

脑内原发性淋巴瘤MRI表现

目的:分析脑内原发性淋巴瘤的MRI表现。方法:回顾性分析17例经病理证实的脑内原发性淋巴瘤的MRI资料,所有病例均行MR平扫及增强扫描,其中2例行弥散加权成像。结果:17例脑内原发性淋巴瘤共34个瘤灶;其中单发8例,多发9例;幕上病灶29个,幕下病灶5个。MR平扫T1WI等信号15个病灶,略低信号19个病灶,T2WI呈等低信号23个病灶,略高信号11个病灶;增强扫描肿瘤均匀强化22个,不均匀强化12个,瘤周轻度、中度水肿各17个病灶。2例共3个瘤灶弥散受限。结论:脑内原发性淋巴瘤磁共振表现具有一定的特征性,认真分析其特点,可提高诊断的准确性。     

儿童注意缺陷多动障碍的功能磁共振成像研究

目的使用功能磁共振成像(functional magnetic resonance imaging，fMRI)方法研究正常儿童及注意缺陷多动障碍儿童在执行高级抑制功能执行-不执行(Go-NoGo)操作任务时脑功能状态及激活模式。方法注意缺陷多动障碍患儿10例与年龄、性别、利手匹配的正常儿童11例执行组块设计的Go-NoGo任务，采集全脑血氧水平依赖对比的fMRI扫描数据，用SPM99软件包进行￡检验统计分析，以获取执行不同任务与静息状态对比的脑功能图像。结果(1)在执行刺激匹配的Go任务时，正常儿童脑激活区主要在左侧丘脑及右侧扣带回，右侧额中回(BA9／10)有小范围激活。注意缺陷多动障碍儿童左侧丘脑激活范围显著减小，右侧基底节区及中脑出现了激活。(2)在执行反应匹配的Go任务时，正常儿童右侧岛叶、扣带回及左侧额叶可见激活。多动症儿童在右侧额中回(BA6／9)可见少量激活。(3)在执行NoGo任务时正常儿童右侧额中回(BA46)为主要激活区，左侧前扣带回、左侧额中回及右侧丘脑可见激活。多动症儿童右侧额叶激活区增多，但主要在BA8区，而前额叶(BA9、10)的激活并不显著，丘脑激活范围及强度较正常儿童均有增加。结论注意缺陷多动障碍儿童存在以前额叶及扣带回前部为主的功能低下脑区，同时有丘脑功能的异常。     

急性脑梗塞早期MRI表现与病理对照研究

目的阻断狗大脑中动脉建立急性脑梗塞动物模型,观察早期MRI表现及其病理改变。材料与方法将16只成年狗随机分为实验组(10只)和对照组(6只)。经颞开颅阻断一侧大脑中动脉(MCA),造成其供应区急性缺血性脑梗塞,只成年狗随机分为实验组(10只)和对照组(6只)。经颞开颅阻断一侧大脑中动脉(MCA),造成其供应区急性缺血性脑梗塞,术后2,4,6,8,12小时行MRI薄层扫描;取出动物大脑观察病理改变,测定不同时相梗塞区T2时间和组织水含量。结果MRI最早2小时表现异常,T2加权像可见尾状核头部、豆状核信号增高;梗塞6小时,MRI可见尾状核、豆状核形成明确梗塞,并出现占位征象。梗塞2小时,电镜下已有缺血水肿改变,4小时光镜下出现脑缺血水肿改变,电镜下见血脑屏障受损。相关分析表明病灶区T2时间变化与组织水含量变化在时序上有密切关系,经t检验差别具显著意义(P＜0．01)。结论本项实验结果表明,MRI可用于脑梗塞早期的诊断,在显示病灶方面,MRIT2加权像优于T1加权像。急性脑梗塞早期MRI表现的病理基础是脑水肿。     

注意缺陷多动障碍儿童语义工作记忆的功能MRI研究

目的 研究注意缺陷多动障碍（ADHD）儿童在语义工作记忆任务下不同脑区的功能状态。方法 ADHD儿童与正常学龄儿童各9名，分别进行行为学评估和功能MR（MR）扫描，刺激任务采用区组（BLOCK）设计的倒退N计数（N—BACK）模式下语义工作记忆任务。MR扫描采用GE3．0 T MR记录提取阶段大脑的反应。结果 ADHD儿童在语义工作记忆任务下激活普遍低于正常组，在1-BACK任务中双侧额中回、额下回、双侧顶上小叶、顶下小叶、右基底节激活低于正常组，而在2-BACK任务中双侧额中回、额下回、双侧顶上小叶、左侧顶下小叶、右基底节及前扣带回激活低于正常组。结论 ADHD儿童的工作记忆功能区包括双侧背外侧前额叶及双侧顶叶存在功能低下，在高负荷的2-BACK任务下并有执行功能区（前扣带回）的激活降低。     

Uncommon posterior cranial fossa anomalies: MRI with clinical correlation

The clinical and MRI findings in two cases of rhombencephalosynapsis (RS) and two of tectocerebellar dysraphia (TCD) with an associated occipital encephalocele were studied to elucidate the clinical picture and embryogenesis of these rare anomalies. To our knowledge, only one case of TCD [1] and four of RS [2, 3] examined by MRI during life have been reported. The clinical picture in the cases of RS was rather constant and there were similarities with TCD. Consideration of the embryogenesis of the neural tube suggests a temporal proximity of the abnormalities, with TCD arising at a slightly earlier time.     

非哺乳期乳腺炎性病变的MRI表现及其与病理的对照研究

目的 探讨非哺乳期乳腺炎性病变的MRI表现及其病理基础.方法 回顾性分析术前行动态增强乳腺MRI检查,且经病理确诊的非哺乳期乳腺炎性病变患者78例.其中27例行DWI检查.观察MR图像上病灶的动态增强特点及DWI表现.病灶内部强化分为环形强化、不均匀强化(Ⅰ型和Ⅱ型)、均匀强化及集簇状强化.观察4种主要病理改变(脓肿、导管扩张、炎性囊肿和其他炎性表现)的出现情况.将MRI和病理结果进行对照.结果 78例中,环形强化55例,不均匀强化Ⅰ型10例,不均匀强化Ⅱ型9例,均匀强化2例,集簇状强化2例.27例行DWI的患者中,17例病灶内部强化为环形强化,在DWI上均呈中央高信号,其病理表现多为炎性囊肿(9例)和脓肿(8例);1例呈环形强化,在DWI上呈周边高信号,其病理表现为炎性囊肿;3例呈不均匀强化Ⅰ型,在DWI上均呈不均匀高信号,其病理表现均为其他炎性表现;6例呈不均匀强化Ⅱ型,在DWI上均呈类圆形或条状高信号,其病理表现为脓肿(5例)及导管扩张(3例).结论 非哺乳期乳腺炎性病变在MRI上具有一定特征,其MRI表现和病理基础有关.     

后部白质脑病综合征的DWI表现及与其可逆性的关系

目的探讨后部白质脑病综合征(PLS)的DWI表现及其可逆性的关系。方法回顾性分析了32例PLS患者的临床和影像学资料,32例均行MRI检查和复查,包括常规T1WI、T2WI、FLAIR及DWI序列;DWI信号表现分为高信号、非高信号组,再根据ADC值是否降低为弥散受限和弥散不受限2类。结果 DWI高信号病灶的可复性与DWI呈等/低信号病灶的可复性经卡方检验比较无统计学差异(P>0.05);结合ADC图,弥散受限组与弥散不受限组之间病灶的可复性有显著统计学差异(P<0.01)。结论 DWI结合ADC图能更可靠地判断PLS的预后。     

儿童白质消融性脑白质病的MRI表现

目的 探讨白质消融性脑白质病(VWM)的MRI特征表现.方法 回顾性分析2008年至2013年间经本院儿科基因确诊为VWM的10例患儿的临床及MR资料.由2名资深的神经放射医师进行阅片,对白质病变部位(大脑、小脑、脑干、胼胝体及内外囊)、范围、信号特点、有无囊变、脑萎缩及基底节受累等进行分析.结果 10例大脑中央白质均弥漫受累,9例部分皮层下白质受累,7例伴U形纤维受累;7例伴有囊变;8例内囊后肢受累,7例外囊受累,8例胼胝体内缘(透明隔缘)受累.2例丘脑和苍白球出现异常信号,6例脑干白质受累,7例小脑白质受累.结论 大脑中央白质出现弥漫对称的异常信号伴囊变是VWM特征性的MRI表现,对该病的诊断具有重要价值.     

儿童Kallmann综合征的影像表现

目的 总结儿童Kallmann综合征(KS)的影像表现,提高对该病的认识.方法 搜集经临床证实且有影像资料的KS患儿13例,患儿均经颅脑MR、左腕骨X线检查,其中8例行腹盆腔B超检查,分析总结其影像表现.结果 13例患儿中,9例双侧嗅球、嗅束缺如;4例一侧嗅球小、嗅束细小或显示不清,另一侧嗅球嗅束缺如.8例双侧嗅沟不同程度浅小,其中2例一侧嗅沟消失;3例一侧嗅沟浅、一侧正常;2例双侧嗅沟正常.3例伴垂体前叶小.6例骨龄落后.B超检查8例中,双侧睾丸均小.结论 儿童KS均有嗅脑发育不良的MRI表现,部分伴垂体前叶发育不良;近半数伴骨龄落后;双侧睾丸均小.     

乳腺叶状瘤的MRI表现及病理对照分析

目的 探讨乳腺叶状瘤(PT)的MR表现及其病理基础.方法 回顾性分析2006年1月至2010年6月期间27例(28个病灶)经手术病理证实的PT患者MRI表现,并与病理学分级结果相对照.采用单因素方差分析、Fisher精确检验及Spearman相关分析比较不同病理分级PT病灶的大小、MRI表现异同及其与乳腺影像报告和数据系统(BI-RADS)分类的相关性.结果 (1)28个PT病灶中,病理学分级为良性、交界性及恶性者分别为4(14.3％)、15(53.6％)和9(32.1％)个.(2)恶性、交界性和良性PT病灶的平均最大径分别为(6.4±3.9)、(5.7±2.2)和(4.8±1.8)cm,差异有统计学意义(F= 287.541,P=0.000),其中良性和恶性病灶间比较差异有统计学意义(P =0.033).(3)与病理学分级对照,在良性、交界性及恶性PT病灶中,T2WI上有低信号分隔者分别为2、13和13个,无低信号分隔者分别为2、2和6个;增强后有裂隙状低信号影者分别为3、3和6个,无裂隙状低信号影者分别为1、12和3个;病灶时间-信号强度曲线为持续型者分别为2、11和1个,平台型者分别为1、2和3个,廓清型者分别为1、2和5个,差异均有统计学意义(x2值分别为7.334、6.765和9.296,P值均＜0.05).(4)将BI-RADS 4a作为可疑恶性病灶,MRI检出病变的准确率为96.4％( 27/28),且BI-RADS分级与乳腺PT的恶性程度呈低度相关(r=0.382,P=0.045).结论 乳腺PT的MRI表现有一定的特征性,病灶大小及MRI的一些特殊征象与其病理学分级呈低度相关.     

Signal intensity correlation of MRI with pathological findings in spinal neurinomas

Summary MR signal intensities at 0.282 T were correlated with the pathological findings in 23 cases of spinal neurinoma. With T2-weighted images (SE-T2WI or RARE-T2WI), all the tumors displayed high signal intensities similar to that of cerebrospinal fluid, indicating long T2 values. It is shown that the long T2 values of neurinomas are caused not only by intratumoral cystic formation, as reported by other authors, but also by intratumoral Antoni B structure, intratumoral micronecrosis and intratumoral vascular malformation. On SE-T1WI, the majority of neurinomas (73.9%) were isointense to spinal cord while the minority (16.1%) were hypointense. The similarity of the T1 values of neurinomas to that of the spinal cord may be related to the abundance of Schwann cells within the tumors, but tumors hypointense to cord and tumors isointense to cord on T1WI showed no significant difference in their gross and microscopic pathology.