Neuroradiologic findings in children with mitochondrial disorder: correlation with mitochondrial respiratory chain defects

Mitochondrial disorders are a heterogeneous group of disorders affecting energy metabolism that can present at any age with a wide variety of clinical symptoms. We investigated brain magnetic resonance (MR) findings in 40 children with defects of the mitochondrial respiratory chain (MRC) complex and correlated them with the type of MRC defects. Enrolled were 40 children with MRC defects in biochemical enzyme assay of the muscle specimen. Twenty-one children were found to have classical syndromes of mitochondrial disorders and 19 children presented nonspecific mitochondrial encephalomyopathies. Their brain MR imaging findings were retrospectively reviewed and correlated with the biochemical defect in the MRC complex. Children with MRC defects showed various neuroradiologic features on brain MR imaging that resulted from a complex genetic background and a heterogeneous phenotype. Rapid progression of atrophy involving all structures of the brain with variable involvement of deep gray and white matter are the most frequent MR findings in children with MRC defects in both classical syndromes of mitochondrial disorder and nonspecific mitochondrial encephalomyopathies. The type of biochemical defect in the MRC complex enzyme did not correlate with brain MR findings in child patients.     

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。     

急性实验性变态反应性脑脊髓炎模型的MRI表现及其病理基础

目的 探讨急性实验性变态反应性脑脊髓炎(EAE)模型的MRI表现及其病理基础.方法 用豚鼠全脑脊髓匀浆诱导EAE大鼠模型(6只),观察其体重变化和临床表现,同时设对照组(6只).在EAE大鼠发病后进行MR常规扫描、钆剂增强扫描,并静脉使用超小超顺磁性氧化铁(USPIO),24 h后行USPIO增强扫描,扫描完毕立即处死大鼠取脑,行脑组织切片的HE染色、髓鞘染色和普鲁士蓝染色.观察MRI和病理检查的异常所见,并进行对照.结果EAE大鼠组在诱导后第8～9天开始体重下降,在第10～11天出现临床症状.MR常规扫描未见明确异常,钆剂增强后仅见脑膜弥漫增厚及增强,USPIO增强扫描可见T2WI上延髓实质内大片低信号区,T1WI可见对应部位的高信号.梯度回波T2*WI比T2WI显示在脑干病灶以外的小脑白质内低信号.临床评分高的大鼠其低信号范围也较大.对照组大鼠未见异常.病理检查发现发病大鼠脑白质内散在血管套袖,部分伴相邻区域的脱髓鞘改变.普鲁士蓝染色发现病灶内巨噬细胞胞质内有蓝染颗粒,沉积部位与T2WI上低信号对应.结论USPIO增强MRI可以揭示常规MRI和钆剂增强成像未能显示的急性EAE病变,活体显示EAE病灶内巨噬细胞的分布,具有重要的研究价值和应用前景.     

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.     

Surface anatomy scanning (SAS) in intracranial tumours: comparison with surgical findings

We evaluated the usefulness of surface anatomy scanning (SAS) in intracranial tumours, comparing it with surgical findings. We examined 31 patients with brain tumours preoperatively. The tumours included 16 meningiomas, 8 gliomas, 4 metastases and 3 others. SAS clearly demonstrated the tumours, allowing them to be distinguished from the structures of the brain surface, including oedema, except in cases of metastasis. SAS clearly demonstrated large cortical veins. SAS is useful for three-dimensional delineation of the brain surface before surgery.     

Central pontine myelinolysis: clinical presentation and radiologic findings

Central pontine myelinolysis (CPM) is a neurologic disorder once thought to be uniformly fatal. With the introduction of CT and MRI there was an increasing number of reports on nonfatal cases of CPM. Nearly all reports on nonfatal cases describe severe clinical syndromes with tetraparesis, bulbar palsy, and coma. We reviewed nine patients with CPM and compared the size of the pontine lesion on MRI and CT with the severity of clinical presentation. Clinical presentation of CPM was highly variable: The symptoms ranged from severe neurologic disorders to mild neurologic disturbances only. Two of nine patients died from CPM. The size of the pontine lesion did not correlate with the severity of the neurologic illness or the final outcome. Mild forms of CPM might be difficult to diagnose clinically. This applies even more for patients with underlying diseases such as Wernicke's encephalopathy, which in itself might cause a clinical picture similar to that of CPM. Central Pontine Myelinolysis is a major differential diagnosis in acute neurologic deterioration indicating pontine damage. Magnetic resonance imaging is the decisive diagnostic tool for CPM. Correspondence to: J. Laubenberger     

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。     

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。     

鼻咽癌放射治疗后脑干放射性损伤的MRI表现

目的探讨鼻咽癌放射治疗后脑干放射性损伤的ＭＲＩ表现。方法分析５１例鼻咽癌经放射治疗后，脑干放射性损伤的ＭＲＩ自旋回波Ｔ１ＷＩ及超快速自旋回波Ｔ２ＷＩ和增强后Ｔ１ＷＩ表现及临床表现。结果脑干放射性损伤的临床表现为肢体麻木、无力或瘫痪及颅神经损伤症状。ＭＲＩ显示中脑、脑桥和延髓内呈斑片状改变分别为２、７及３例；脑桥基底部广泛受累９例；脑桥基底部下份及延髓前上份者３０例。自旋回波Ｔ１ＷＩ病灶均呈低或等信号改变；超快速自旋回波Ｔ２ＷＩ呈等、高信号混杂改变，脑桥水平病灶内高信号呈横行条纹状。增强后扫描显示病灶区无强化者９例，斑点状强化者３例及不规则花环状强化者３９例。占位效应与病灶的大小不相称。１４例经治疗后ＭＲＩ复查，４例病灶消失，８例病灶形态及位置无变化，２例病灶增大。结论ＭＲＩ可显示脑干放射性脑病特征；临床症状与ＭＲＩ追踪表现可不完全一致     

Bone bruises: MR characteristics and histological correlation in the young pig

PURPOSE: To correlate magnetic resonance (MR) signal characteristics of bone bruises with histological findings. MATERIALS AND METHODS: In 14 tibiae of young pigs, bone bruises were created in the proximal tibial metaphysis. The signal intensity seen on the MR images were correlated with histological findings. The following findings were evaluated: (a) changes of signal intensity on the tibiae; (b) changes of histology on the tibiae; and (c) changes of (a) and (b) on follow-up examinations. RESULTS: We observed three types of injuries on T1-weighted images: focal or diffuse low signal, normal signal and linear low signal intensities. Severe hemorrhagic areas showed low signal intensities on all sequences of MR imaging. Fast spin-echo (FSE) T2-weighted images showed a more distinct low signal intensity than T1-weighted images. FSE short tau inversion recovery (STIR) and FSE fat saturated (FSE-FS) T2-weighted images showed similar signal intensities with FSE T2-weighted images. FS T1-weighted enhanced images showed low signal intensities with variable enhancements. Upon histological examination, hemorrhages and edemas were prominent at the subcortical areas of the contusion sites. The areas of dense, low signal intensities in all imaging sequences showed signs of severe hemorrhage. The areas of diffuse low signal and enhanced areas showed mixed areas of hemorrhages and edemas. Follow-up MR imaging showed evolution of the processes of hemorrhages and edemas with fatty marrow changes. CONCLUSIONS: MR imaging can depict changes in the bone marrow resulting from direct injury to the bone. MR imaging is a useful tool for evaluating the evolution of bone bruises.     

软骨母细胞瘤MRI及X线平片和CT的表现特征

目的 研究软骨母细胞瘤的影像表现,探讨其MRI与X线平片、CT征象的对应关系.方法 分析16例经手术、病理证实的良性软骨母细胞瘤的影像资料,总结其MRI表现与X线平片、CT征象的对应关系.结果 16例软骨母细胞瘤均位于骨骺,大小为0.9 cm×0.8 cm×1.0 cm～4.8 cm×4.3 cm×5.1 cm,呈不同程度的分叶状.在T1WI上以等、低信号为主,T2WI上呈混杂信号,CT上为软组织密度,内见钙化和更低密度区.边缘呈长T1、短T2信号,在CT上表现为硬化边.MRI可见病灶周围有骨髓水肿,在X线和CT上表现为骨质硬化区.病灶邻近软组织肿胀.MRI显示骨膜异常9例,8例与病灶不相邻;X线和(或)CT显示骨膜新生骨6例.MRI显示关节积液12例,CT显示6例.MRI上病灶均呈不均匀强化,骨髓水肿、骨膜反应和软组织肿胀均见强化.软骨母细胞瘤在扩散加权成像(DWI)上呈等、高信号,在MR平扫中的等T1、等T2成分和长T1、长T2成分,以及骨髓水肿、骨膜反应和软组织肿胀在DWI上均呈高信号.结论 MRI和X线平片、CT从不同方面反映软骨母细胞瘤的病理改变,联合应用不同检查手段可更全面显示软骨母细胞瘤的特点.     

环形表面线圈MTR定量的可行性研究

目的通过实验研究探讨3in（lin＝2.54cm）表面线圈磁化传递率（MTR）定量的可行性，方法应用临床MR机及其所属3in环形表面线圈，对5只大白鼠和胶质溶液模型分别进行扫描，并测量不同浓度的胶质模型和大白鼠桥脑及额叶的MTR值，分析其相关性。结果随着远离线圈表面距离的增加．虽然图像的信号逐渐减低，但是MTR值不发生变化。MTR同胶质浓度呈直线正相关。并且在大白鼠脑显示出桥脑高于额叶。结论3英寸环形表面线圈不但可以得到小体积被检对象的高分辨率图像，而且还可以用于MTR定时分析.     

基于MR三维梯度回波与扩散加权成像序列的脑表面重组技术比较

目的 使用MR三维梯度回波（3D flash）序列和扩散加权成像（DWI）序列的扫描图像进行脑表面三维重组，对两种方法显示脑表面结构的能力、价值与限度及临床应用等进行比较和探讨。方法 对30名正常人行头颅3D flash和DWI检查。通过容积重组显示脑表面解剖结构。同一组医生对两种方法重组图像进行评价和评分，并比较结果。结果 基于3D flash重组的各脑表面结构清楚显示，平均得分均在2．50分以上。基于DWI的重组图像能够较好地显示中央前回、中央后回、顶上小叶、额上回、中央前沟、中央沟、中央后沟、顶间沟及额上沟等结构，平均得分2．60～2．75分，缘上回、角回、额中回、额下回、颞上回、外侧沟和额下沟等结构显示较差，平均得分1．67～2．48分，颞中回、颞下回、颞上沟及颞下沟等显示很差，平均得分仅0．88～1．27分。比较两种方法的平均得分，基于3D flash重组优于基于DWI的三维重组，差异有统计学意义，P值均〈0．01。结论 基于3D flash重组能够显示真实的脑表面主要脑沟、脑回和脑裂，对脑解剖形态的研究和定位诊断有重要意义。基于DWI的三维脑表面重组能比较满意地显示顶叶、额叶的主要表面结构，扫描和重组快速，有一定实用价值。     

Radiological and histological findings in spinal intramedullary angiolipoma

We report an intramedullary angiolipoma with spinal cord compression studied by MRI, angiography and CT. Angiolipomas of the spine are rare benign tumours containing vascular and mature adipose elements. They are epidural in more than 90 % of the cases; only three cases of intramedullary angiolipoma are described. The clinical picture is nonspecific, but MRI and CT suggest the diagnosis. Accepted: 16 December 1998     

使用磁共振成像技术在体测定正常人脑结合水和自由水质子密度

目的　活体状态下测定人脑结合水和自由水密度。方法　将梯度回波序列信号强度公式代入磁化传递率计算公式中,推导出一个结合水和自由水密度的计算公式。测定７ 名正常人脑各种组织结构在式中的参数,包括质子密度、磁化传递率（ＭＴＲ） 及附加和不附加偏共振（ｏｆｆｒｅｓｏｎａｎｃｅ）射频脉冲时测定的两种Ｔ１ 弛豫时间。将这些参数代入新公式中计算出结合水和自由水质子密度。结果　脑灰质的结合水和自由水密度分别是５６５－７±１１５－９ 和８１１－５ ±１１１－０ ,高于脑白质的结合水密度５１２－３±１０２－３ 和自由水密度６３２－５ ±６５－５ （ Ｐ＜ ０－０１） ,脑灰质ＭＴＲ 为０－２６３ ±０－０２９,低于脑白质的０－３４４ ±０－０２８ （ Ｐ＜ ０－０１） 。结论　结合水是区别于ＭＴＲ 的另一个分辨组织性状的参数,新公式在数学上指出了两者之间的联系。     

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。     

Comparison of the precision of two standardized co-ordinate systems for the quantitation of brain anatomy: preliminary results

We assessed reproducible definition of two standardized co-ordinate systems for intersubject analysis of brain images. The baselines in the two co-ordinate systems were a modification of the canthomeatal (inCM) line and the anterior-posterior commissural )AC-PC) line. Axial spin-echo MR images of four subjects at 1.5T were used. Operator error was computed from the replicate analyses of two operators. The mCM line was determined by the lens of the eye and the internal auditory canal, and the AC-PC line was determined by the intersection of the AC and PC with the interhemispheric fissure. Reproducibility of the mCM markers (SD=0.59 mm) did not differ significantly from that of the AC-PC line (SD=0.68 mm). The measurement error of the angle of the baseline (), however, was more than 7 times as large for the AC-PC line as for the mCM line. An additional error affecting the rostrocaudal rotation of the co-ordinate systems, attributable to the distance between the anatomic markers, was 2.1 and 3.6° (3 mm and 5 mm slice thickness) for the mCM co-ordinate system and 8.2 and 11.0° (3 mm and 5 mm slice thickness) for the AC-PC system. The AC-PC line based co-ordinate system is therefore, less reproducible than the mCM line based system. this could be improved if a combination of axial and sagittal images were used for the definition of the AC-PC line.     

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。     

Spinal epidural abscess: correlation between MRI findings and outcome

Our purpose was to determine if specific MRI findings in spinal epidural abscess (SEA), at the time of diagnosis, are associated with the clinical outcome. The clinical records and MRI studies of 18 patients with SEA were reviewed and follow-up was obtained from the outpatient medical record, telephone interview, or both. The association between findings on contrast-enhanced MRI and clinical outcome (weakness, neck or back pain, and incomplete functional recovery) was evaluated. With univariate analysis, narrowing of 50 % or more of the central spinal canal (P = 0.03), peripheral contrast-enhancement (P = 0.05), and abnormal spinal cord signal intensity (P = 0.05) were associated with weakness at follow-up. Persistent neck or back pain was associated with spinal canal narrowing (P = 0.02), peripheral contrast-enhancement (P = 0.02), and an abscess longer than 3 cm (P = 0.04) on MRI. Incomplete clinical recovery was associated with both abscess length (P = 0.01) and the severity of canal narrowing (P = 0.01). Abscess length, enhancement pattern, and severity of canal narrowing can be incorporated in a grading system that can be used to predict outcome. Received: 9 September 1998 Accepted: 6 March 1999     

脊索瘤的磁共振成像诊断及鉴别诊断

目的 探讨脊索瘤的磁共振成像(MRI)特征,提高其诊断的准确性.方法 对15例经病理证实的脊索瘤MRI影像进行分析及总结,分析病变的发生部位、形态、大小、边缘、信号等影像学特征.结果 斜坡、骶尾椎、颈部3个部位的MRI表现在T1加权图像呈低信号,其间部分可夹杂多个斑点状的高信号,系出血及黏液变所致;在T2加权像上均呈不均匀高信号.结论 CT在显示骨质破坏及钙化上有优势,但是在显示脊索瘤方面MRI具有多方位成像、无骨骼伪影的特点,肿瘤及比邻组织的显示更为优越,有利于临床诊断及拟定治疗方案.