上矢状窦栓塞大脑髓静脉改变的SWI研究

目的:利用磁敏感加权成像(SWI)技术探讨上矢状窦栓塞后大脑髓静脉的改变。方法:对10例上矢状窦栓塞患者和年龄、性别相匹配的10例健康志愿者行常规MRI、MRV和SWI,应用计算机后处理软件对SWI图像进行处理,得到校正后的磁矩图和相位图,将大脑髓静脉增多扩张脑白质区作为病变组、其对侧镜像正常脑白质区为对照组1,健康志愿者与病变组相同位置脑白质区为对照组2,分别测量相位值,进行比较,统计学分析采用单因素方差分析。结果:病变组选择髓静脉增多扩张脑白质区37处测得相位值为-0.571～0.104,平均-0.051;对照组1相位值为-0.047～0.079,平均0.010;对照组2相位值为-0.045～0.056,平均0.014;病变组相位值低于对照组1和对照组2,差异有统计学意义(P<0.001);对照组1和对照组2相比,二者无显著差异(P=0.790)。结论:磁敏感加权成像(SWI)能明显显示上矢状窦栓塞患者大脑髓静脉的增多、扩张,并可利用相位信息为其提供量化依据。     

大脑矢状断层脑回表盘定位的影像解剖学研究

随着医学影像诊断技术的飞速发展及其在临床研究中的广泛应用,大脑皮质功能定位及其小病灶的早期定位诊断越来越受到重视,许多学者开始用脑断层标本、CT、MR图像等进行层面上的定位研究.笔者采用脑MRI与相应脑断层标本的对照观察,借助表盘定位法在矢状面MR图像上对脑回进行定位,旨在为大脑皮质病变的影像定位诊断和脑功能研究提供新的形态学定位方法.     

正常成人环杓关节及毗邻结构的MSCT研究

目的 :探讨环杓关节及相邻结构的CT表现及多层螺旋CT(MSCT)容积重组对环杓关节结构的显示能力。方法 :2 8例无任何喉部症状的健康志愿者 ,在平静呼吸及Valsalva呼吸状态下分别行喉部薄层扫描并采用容积再现 (VR)技术进行图像三维重组 ,比较轴位与容积再现图像对环杓关节的显示情况。结果 :CT轴位图像上两侧环杓关节、梨状窝、声门裂显示对称者分别为 2 2例 (78.6% )、2 3例 (82 .1% )、2 6例 (92 .9% ) ,声带突、肌突显示率分别为 3 9.3 %、46.4%。VR图像上显示两侧环杓关节对称者 2 7例 (96.4% ) ,声带突、肌突显示率分别为 5 3 .6%、60 .7%。CT轴位图像与VR图像对环杓关节的显示差异有显著性意义 (t=4.994,P <0 .0 1)。结论 :正常环杓关节、声门裂、喉室均对称。MSCTVR图像对评价环杓关节解剖结构明显优于轴位图像。     

多发性硬化性脑萎缩MRI评估及其临床意义

目的;研究多发性硬化的脑萎缩和神经机能缺损以及与病程的相关性,分析脑结构萎缩与病残程度的关系。方法：多发性硬化患者42例,其中复发缓解型（RR）25例,平均年龄31岁（17-41岁）;进展型（SP）17例,平均年龄38例（32-53岁）,健康对照组15例。据MRI多发性硬化病灶计算病损的体积。结果：MS患者的大脑白质、幕下结构、胼胝体容积较健康对照组明显减少（P＜0.01),上颈髓减小44.4%、小脑减小20.3%、脑干减小23.1%、胼胝体减小21.8%。SP组较RR组上的颈髓和大脑白质萎缩更为明显（P＜0.05至P＜0.01)。脑室扩大（r= 0.50,P＜0.01)与胼胝体体积减小（r=-0.55,P＜0.01)之间有明显相关性,病人组上颈髓萎缩与临床神经机能障碍明显相关,临床技能评分（SNRS）减少与上颈髓萎缩具相关性（r= 0.48,P＜0.01）,在脑白质上结构变化与对照组比较与病程明显相关（r=-0.47,P＜0.005),大脑白质萎缩与SNRS亦相关（r=0.41,P＜0.05)。中枢神经结构萎缩在多发性硬化的RR组、SP组之间的差异,尤其幕下结构在复发缓解型多发性硬化有更明显的变化。提示急性炎症所致的中枢性传导束变性,可能在多发性硬化中是较早发生的病理过程。MRI对多发性硬化的随访与预后评估有一定意义。     

探讨最适宜评价下颌骨髁状突骨皮质的颞下颌关节MR成像序列——以微CT为参考标准的尸体研究

摘要目的以尸体标本的微CT成像结果作为标准,探讨最适宜评价下颌骨髁状突骨皮质的颞下颌关节MR成像矢状位序列。方法将8例头部标本(平均年龄81岁)共16例颞下颌关节进行MR成像。两名观察者在所有MRI矢状位序列上测量了下颌骨髁状突前、上及后部的骨皮质厚度(客观分析),并且观察是否有骨皮质变薄、骨质侵蚀或骨表面不规则以及皮质下囊肿和髁状突前部骨赘形成(主观分析)。以微CT成像结果作为参考标准进行统计学分析。     

正常恒牙及牙槽突多层螺旋CT表现

目的 探讨正常恒牙及牙槽突的多层螺旋CT(MSCT)表现.方法 30例正常牙(牙合)恒牙与牙槽突应用多层螺旋CT扫描,窗宽3000～5000 HU、窗位1200～1500 HU进行观察.所有图像数据均进行多平面重建、齿科软件全景重建及三维表面遮盖重建.结果 牙各部分无机物含量不同而在MSCT图像上显示为密度不同的多层结构,由高到低分别为牙釉质、髓周牙本质、外周牙本质与牙骨质、牙髓.牙周膜位于牙周呈低密度影,厚度均匀.牙槽突骨皮质连续,骨小梁走行呈线状及网状.结论 MSCT检查可以清晰显示恒牙及牙槽突的结构,多平面重建及齿科软件全景重建及三维表面重建有助于其相邻关系的判断.     

牙颌专用CT的颞颌关节成像技术

目的：探讨牙颌专用CT的颞颌关节成像技术及临床应用价值。材料和方法：对162例疑有颞颌关节病的患者行牙颌专用CT的颞颌关节检查,对感兴趣区影像重建,获取临床常用的轴位、冠状位、矢状位外,增加平行于髁状突长轴的斜位、垂直于髁状突长轴的斜位及双侧髁状突曲面重建影像分析其表现并评估其应用价值。结果：162例受试者均获满意的重建影像。平行于髁状突长轴的斜位和垂直于髁状突长轴的斜位,显示了颞颌关节的真实形态。双侧髁状突曲面成像,将水平角不在一条直线上的双侧髁状突长轴或短轴层面,重建在一幅影像内,方便了双侧髁状突相同体位影像的对比观察。结论：牙颌专用CT成像软件系统可以对颞颌关节骨性结构行多种体位、角度的重建及径值的测量。     

动脉硬化性脑白质病的CT表现与临床分析

目的 :探讨动脉硬化性脑白质病的临床与CT表现特点。方法 :收集 10 0例动脉硬化性脑白质病的临床与CT资料进行综合分析。结果 :10 0例的CT表现为 :弥漫性脑白质低密度改变 ,主要分布在双侧脑室旁及半卵圆中心白质区 ,病灶多呈条带状及月晕状。合并脑萎缩 90例 ;脑梗塞 76例 ,其中 2 5例有大的梗塞灶 ,其余为腔隙性梗塞 ;脑出血 9例 ,其中位于壳核 5例 ,丘脑 3例 ,小脑 1例 ;有 15例伴发基底节区软化灶。增强扫描 8例 ,显示病灶无明显增强。结论 :动脉硬化性脑白质病是发生于老年人的缺血性脑血管病 ,高血压动脉硬化是其主要发病因素。     

螺旋CT三维重建诊断下颌骨髁状突矢状骨折

目的：探索三维CT对下颌骨髁状突矢状骨折（SFMC）的临床应用价值。分析SFMC好发位置及临床特点。材料和方法：对25例（50侧）疑有髁状突骨折的患者作了螺旋CT三维重建的检查，结合横断位和冠状位二维CT图像，确定SFMC。结果：11例（11侧）SFMC占检出的38侧髁状突骨折的28.9%(11/38)，其中发生在髁状突中、外1/3交界段者9侧，髁状突内侧1/3段者2侧。4例SFMC并发下颌其他部位的骨折。结论：三维CT对诊断SFMC有着重要意义，SFMC好发于髁状突的中、外1/3交界段，其原因可能与髁状突的解剖特征及其与邻近结构的空间关系有关。     

蝶筛区域解剖结构的CT评价及对功能性内窥镜鼻窦外科的指导意义

目的探讨CT对蝶筛区域解剖结构的评价能力,以期为功能性内窥镜鼻窦外科手术提供帮助。材料和方法冠状和横轴位薄层CT扫描54例无病变的蝶筛区域,并重建矢状位图像。结果CT图像中蝶上筛房出现率13.0％。蝶窦气化CT分型中,甲介型占8.3％,半鞍型占51.9％,全鞍型占39.8％。蝶窦中隔居正中位置占24.1％。蝶窦的其他变异有翼突气化、前床突气化、蝶骨大翼气化和蝶骨小翼气化。视神经管纵轴与蝶筛窦的毗邻关系在CT图像上分为三型,视神经管横轴对蝶筛窦的压迫关系分为四型,并统计出各型的分布情况。结论CT扫描能显示蝶筛区域与功能性内窥镜鼻窦外科手术有关的绝大部分解剖结构及其变异,对手术有很大的指导作用。     

MR and CT of tuberous sclerosis: linear abnormalities in the cerebral white matter

A review of MR and CT images in five patients, 8 months to 22 years old, diagnosed as having tuberous sclerosis, revealed linear abnormalities in the cerebral white matter. A linear abnormality connecting a subependymal nodule to a subcortical lesion was shown in two patients as an area of hypointensity on T1-weighted MR images and as an area of hyperintensity on T2-weighted images. These appeared as faintly high-density areas on CT images. Seventeen linear abnormalities extending from the ventricle to the cortex with a subependymal nodule or subcortical lesion on each end were visible in all five patients as areas of hyperintensity on the T2-weighted images. On the T1-weighted images, only nine hypointense lines were noted. CT scans did not show these latter lines. Linear abnormalities in cerebral white matter are suggestive of lesions of demyelination, dysmyelination, hypomyelination, or lines of migration disorder. MR imaging, especially T2-weighted, is particularly sensitive in detecting these abnormalities.     

Magnetic resonance images of tuberous sclerosis

Summary The cerebral lesions in tuberous sclerosis are of three kinds: subependymal nodules, cortical tubers, and cluster of heterotopic cells in the white matter. Understanding of these hamartomas is still incomplete even with modern imaging modalities. Magnetic resonance (MR) images of ten patients with tuberous sclerosis were reviewed and compared to computed tomographic (CT) scans and to the clinical severity of the disease. T2 weighted spin echo (TR=1800, TE=120) images and inversion recovery (TR=2100, TI=500–600, TE=40) images were obtained at the same axial planes. Periventricular nodules were better seen, because of their calcifications, with CT than with MR imaging. They were demonstrated as iso- to low intensity depending on the amount of calcification on T2 weighted images, and as a similar intensity to the white matter on IR images. Small peripheral lesions in the hemispheres, which were only occasionally seen as small low density areas on CT scans, were well demonstrated on MR images. These foci were hyperintense on T2 weighted images, and hypointense on IR images. Exact location of these was not in the cortex, but in the subcortical white matter. The findings indicate that these foci represent the pathologically well known demyelinating foci, which are commonly present under the cortical tuber, but may be independent of them. Cortical tubers were not confidently identified, which suggested that they might have similar intensity to the cortical gray matter. Some of the parenchymal calcifications other than periventricular nodules showed identical MR signal intensities to periventricular nodules, and the rest of the parenchymal calcifications had similar intensities to the subcortical lesions. This indicates that parenchymal calcifications can occur in the demyelinating white matter as well as in the heterotopic tubers in the white matter. The severely mentally retarded patients tended to have a higher number of subcortical lesions and no correlation was noted between the severity of mental retardation and either the number of periventricular nocules or ventricular dilatation.     

Sporadic meningioangiomatosis: imaging findings with histopathologic correlations in seven patients

Introduction

Meningioangiomatosis (MA) is a rare benign cerebral lesion. We aimed to evaluate the CT and MR features of sporadic MA, with a focus on the correlation between imaging and histopathologic findings.

Methods

CT (n?=?7) and MR (n?=?8) images of eight patients (6 men and 2 women; mean age, 12.8 years; range, 4–22 years) with pathologically proven MA were retrospectively reviewed. After dividing the MA lesions according to their distribution into cortical and subcortical white matter components, the morphologic characteristics were analyzed and correlated with histopathologic findings in seven patients.

Results

CT and MR images showed cortical (n?=?4, 50 %) and subcortical white matter (n?=?7, 88 %) components of MA. All four cortical components revealed hyperattenuation on CT scan and T1 isointensity/T2 hypointensity on MR images, whereas subcortical white matter components showed hypoattenuation on CT scan and T1 hypointensity/T2 hyperintensity on MR images. Two cortical components (25 %) demonstrated enhancement and one subcortical white matter component demonstrated cystic change. Seven cases were available for imaging-histopathologic correlation. In all seven cases, the cortex was involved by MA and six patients (86 %) showed subcortical white matter involvement by MA. There were excellent correlations between the imaging and histopathologic findings in subcortical white matter components, and the accuracy was 100 % (seven of seven); whereas there were poor correlations in cortical components, and the accuracy was 43 % (three of seven).

Conclusions

The cerebral cortex and subcortical white matter were concomitantly involved by MA. Subcortical white matter components of MA were more apparent than cortical components on CT and MR imaging.     

MR of Leigh's disease (subacute necrotizing encephalomyelopathy)

MR images of three patients with Leigh's disease (subacute necrotizing encephalomyelopathy) were compared with CT findings. In all patients typical lesions in the basal ganglia were identified with both MR and CT. In two patients MR permitted identification of additional lesions not detected with CT. In one patient progression of MR abnormalities over a 4-month period correlated well with clinical deterioration in neurologic status. T2-weighted images with a repetition time (TR) greater than 1950 msec and an echo time (TE) greater than or equal to 60 msec or inversion-recovery images with a 50-msec TE, 1213-msec inversion time, and 3000-msec TR were advantageous in identifying multiple necrotic lesions in the brainstem, deep gray matter, periventricular white matter, and cerebral cortex. In this series MR was more sensitive in detecting and localizing multifocal necrotic lesions of Leigh's disease than CT was, and thus may be a useful diagnostic tool for patients with the appropriate clinical and laboratory abnormalities.     

Dynamic computed tomography study of the brain.

The dynamic computed tomography (CT) study of the brain consists of the rapid intravenous injection of 49 ml of radiographic contrast material in 7 sec followed by serial 5 sec CT scans with interscan times of only 1 sec. The data from these scans can be reprocessed to create 12 segmented images in 35 sec. When small samples of four to six pixels of cortex are examined by the cursor, sharp rises of 20 to 25 CT units (500 scale) are seen on the time--density curves. Samples of white matter are usually no more than 2 CT units. When larger cursor samples of 220 to 255 pixels including cortex and white matter are examined, the time--density curves represent a combination of these two patterns. Comparison between symmetrical areas in the two hemispheres generally shows parallel curves in controls. The studies provide high resolution cerebral perfusion images. In ischemia secondary to ipsilateral carotid stenosis, there is depression of the up-slope and a depressed and late peak. Infarctions show a flat perfusion curve. Several patterns in brain tumors are illustrated. The study, simple to perform, adds significant perfusion information to the previously static CT examination of the brain.     

职业性急性CO中毒脑CT的观察

目的 探讨CT对职业性一氧化碳(CO)中毒脑部CT表现的特征及其与治疗效果和预后的相互关系。方法 对35例职业性一氧化碳中毒的患进行了两个月至半年的CT观察及随诊。结果 一氧化碳中毒脑CT图象上低密度区的好发部位在脑白质范围以侧脑室额角附近(92％)和半卵圆中心(79％)为主：在脑灰质范围以苍白球(63％)和额叶皮质区(38％)为主。结论 阳性表现率与临床症状的严重程度成正比，脑CT阴性表现，良好痊愈的占多数(71％)，而重残和持续植物状态，脑CT表现100％为阳性。     

Imaging cortical anatomy by high-resolution MR at 3.0T: detection of the stripe of Gennari in visual area 17.

The brain can be parcellated into numerous anatomical and functional subunits. The classic work by Brodmann (Vergleichende Lokalisationslehre der Grosshirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues. Leipzig: Barth; 1909) identified areas of the cerebral cortex based on histological differences. An alternative to his cytoarchitectonic approach is the myeloarchitectonic approach. MRI has excellent white/gray matter contrast in the brain due to the presence of myelin, and thus seems uniquely suited for in vivo studies of cortical myeloarchitecture. Here it is demonstrated that the stripe or stria of Gennari can be consistently detected in human occipital cortex. T(1)-weighted images obtained at 3T from six of 10 normal volunteers, with resolutions of 350 x 350 x 600 mu clearly demonstrate this myelin-rich intracortical layer. It is concluded that the striate cortex (area 17 of Brodmann) of the human brain can be delineated in vivo on T(1)-weighted images, potentially enabling detection of specific cortical boundaries within individual brains.     

一氧化碳中毒的CT诊断

目的探讨一氧化碳中毒的脑部CT特征。方法回顾性分析了18例一氧化碳中毒病人的脑部CT征象。结果双侧苍白球对称性低密度与脑白质低密度为最常见征象,前者占所有病例56%,具有特征性。脑皮质、海马、小脑病理改变也可发现。结论脑CT检查有助于临床确立诊断。     

T1 hyperintensity in the pulvinar: key imaging feature for diagnosis of Fabry disease

BACKGROUND AND PURPOSE: Fabry disease (FD) is an inborn error of glycosphingolipid metabolism. To date, no specific neuroimaging features have been elucidated to help in making the diagnosis of this disorder. The purpose of this study was to determine whether the finding of T1 shortening in the lateral pulvinar is a useful finding in the imaging diagnosis of FD and to deduce the relationship of this finding to the pathophysiology of the disease. METHODS: We studied T1- and T2-weighted images obtained in ten patients (nine male and one female) with FD with an age range of 19-59 years. The images were examined for anatomic aberrations and areas of abnormal signal intensity (SI) in both gray matter and white matter. The SI of deep gray matter was evaluated qualitatively and semiquantitatively, relative to the SI of CSF or the genu of the corpus callosum. Gradient echo MR images and axial noncontrast CT images were available for one patient. RESULTS: Seven of 10 patients showed small areas of T2 prolongation in the white matter of the cerebral hemispheres. Despite the known propensity for vascular disease in these patients, only one had cortical infarction. Bilateral T1 shortening in the lateral pulvinar was recognized in at least seven patients, all over the age of 30 years, who also had small areas of T2 prolongation in the white matter. CT and gradient echo images in one patient revealed no evidence of calcification or metallic deposits in the pulvinar. CONCLUSION: Bilateral T1 shortening in the lateral pulvinar is a common finding in FD and may be useful in suggesting this diagnosis.     

Cystlike white matter lesions in tuberous sclerosis.

PURPOSETo investigate the presence of small cystlike structures in the cerebral hemispheric white matter on MR images of patients with tuberous sclerosis.METHODSThe MR images of 18 consecutive patients with tuberous sclerosis were reviewed retrospectively.RESULTSEight of the 18 patients were found to have cystlike structures in the cerebral white matter. The signal intensity of these lesions was isointense with cerebrospinal fluid on T1-, proton density-, and T2-weighted images. Four patients were imaged with a fluid-attenuated inversion recovery sequence, which in each case also showed fluid-type signal in these areas. Three of the patients had CT for correlation, and these scans supported the diagnosis of cystic lesions. Cysts ranged in number from one to 12 per patient and were usually smaller than 1 cm. The most common location was adjacent to the occipital horn or trigone of the lateral ventricle (six of eight patients). Less frequent sites were near the frontal horns, in the corpus callosum, and in the deep white matter near the body of the lateral ventricle. Cysts in five patients were either immediately adjacent to a cortical tuber or in the center of a white matter dysplastic lesion. A cyst in one patient had septa, and none of the cysts enhanced.CONCLUSIONSCystlike structures in the cerebral hemispheric white matter were seen on the MR images of 44% of 18 patients with tuberous sclerosis. Whether these findings represent cystic degeneration of dysplastic tissue or are unrelated to the disease process of tuberous sclerosis is unknown. More than one pathogenesis may exist.