成人大脑中央沟在冠状面MRI上的定位

目的：探索大脑中央沟在冠状面MRI上的准确定位。方法：随机选用成年男性头部标本30例、活体健康成年男性6例,以经连合间线中点的垂线为基线,获得4mm层厚的颅脑MR冠状面图像;将头部标本开颅取脑,重要脑回着不同颜色,切制与MR扫描一致的脑断层标本。将脑断层标本与颅脑MRI相对照,统计有关结构的出现率,以确定中央沟在冠状面MRI上的定位。结果：在中央沟首次出现的断面上,背仙是丘脑的出现率左侧为93%、右侧97%,锥体束的出现率左侧为20%、右侧13%;在胼胝体压部后缘断面上,中央沟几近消失,大脑外侧面中央沟出现率两侧均为33%。结论：中央沟首次出现在背侧丘脑显现而锥体束尚未出现的1-2个断面上;在锥体束出现的断面上,外侧沟上方可以3大髓突辨认额上回、中央前回和中央后回,中央前、后回之间为中央沟;至胼胝体压部后缘断面,中央沟大多消失。     

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。     

前交叉韧带斜冠状面薄层解剖断面与MRI表现对照研究

目的对冰冻膝关节前交叉韧带（ACL）斜冠状面薄层解剖断面与正常人膝关节MRI特点进行对照研究，为ACL损伤分级诊断建立基础。方法1例（1只）膝关节标本行斜冠状面MRI确定角度，冰冻后沿斜冠状面1mm层厚铣切，观察ACL薄层解剖特点。选择50名正常人对其ACL进行MR斜冠状面扫描，观察ACL的MRI特点。结果1只膝关节标本的ACL在斜冠状面薄层断面清晰显示其全程走行，清晰地显示ACL前内束与后外束，前内束从股骨髁附着点后上方区自后向外侧及前内侧走行，止于髁间棘附着区前内侧方，后外侧束从股骨髁附着点前下方区，自后外侧及外下走行，止于髁间棘附着区后外侧方。斜冠状面MRI能够显示50名正常人ACL全程，显示率为100％。MRI能够区分ACL前内束与后外束结构，显示前内束自后外侧向前内走行，止于髁间棘附着区前内侧方，后外束自后外侧向外下走行，止于髁间棘附着区后外侧方。MRI显示ACL走行与薄层断面显示的走行一致。结论斜冠状面是观察ACL的最佳方位，临床对怀疑ACL损伤的患者必要时行MR斜冠状面扫描。     

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。     

脑池段展神经及相关动脉MRI与解剖断层标本的对比研究

目的：研究展神经及相关动脉的正常表现和相互关系，获得正常MRI和断层解剖资料。方法：在MR三维积极干预稳态（3D—CISS）序列的多平面重组图像上观察57名正常体检者的展神经解剖特点及其与小脑前下动脉（AICA）等血管的关系，其中20名同时行时间飞跃（TOF）序列血管成像。将正常体检者的展神经成像结果与尸体断层切片及头颅标本3D—CISS序列成像结果进行对照。结果：（1）展神经在斜横断面、斜矢状面重组图像上以96．5％（110／114）的几率清楚显示，冠状面重组图像上以94．7％（108／114）的几率清楚显示；20名体检者的3D—TOF序列重组图像上不能清楚显示展神经。（2）103支展神经从桥脑延髓沟发出，7支从紧靠桥脑延髓沟的脑桥表面发出；显示的展神经全部以1支神经根丝连于脑干；面神经丘显示几率为100％（114／114），Dorello管的显示几率为95．6％（109／114）。（3）AICA是显示率最高的动脉，74．7％（71／95）的AICA与展神经接触。（4）将正常体检者的展神经成像结果与尸体3D—CISSMRI及断层切片标本所显示的展神经相对照，显示具有良好的对应关系。结论：3D—CISSMRI可以显示展神经及相关动脉血管的解剖特点；面神经丘和Dorello管是识别展神经的重要解剖标志。     

中英文双语者语义加工的词频相关性磁共振脑功能成像

目的通过对高度流利的中英文晚双语者词频相关性语义判断任务的fMRI研究，探讨语言加工相关脑功能区、词频效应及中英文加工脑功能区可能存在的差异。资料与方法对10名健康志愿者行中文高频、中文低频、英文高频、英文低频语义判断任务，比较不同任务各脑区激活强度及范围的差异。结求语义相关判断任务激活双侧Broca区（BA44、45）、前额叶背外侧（BA9、46）、额叶内侧面（BA6、32、24），颞中回后部（BA21），左侧角回（BA39）和右侧缘上回（BA40）。中文任务词频效应出现在左侧Broca区：英文任务在双侧Broca区。英文高频大于中文高频任务的脑区为双侧Broca区和右侧颞中回后部；中文高频大于英文高频任务的脑区为双侧扣带回前部。结沦词频效应即熟练程度差异影响语言加工相关脑区的激活强度及范围；中英文两种语言激活脑区大部分相互重叠．但仍有差异。     

脑肿瘤引起的运动性失语的功能磁共振研究

目的探讨脑肿瘤引起的运动性失语脑内代偿情况。方法左侧Broca区肿瘤患者患者共13例,根据位置特点分为两组:一组为左侧Broca区脑肿瘤,未侵犯左侧额中回或额叶背外侧区;另一组为左侧Broca区脑肿瘤,侵犯左侧额中回或额叶背外侧区;对照其脑内代偿脑区的异同。正常健康志愿者20人,均为右利手。检查者均完成图片命名任务。AFNI软件处理实验数据。统计分析采用SPSS 12.0分析软件。同一感兴奋区(ROI)比较采用两样本t检验。结果①左侧Broca区脑肿瘤,未侵犯左侧额中回或额叶背外侧区:5例。激活脑区如下:左侧Broca周边脑区:BA46区(5/5);BA10区(3/5)。右侧Broca区激活;双侧额中回及双侧额叶背外侧区激活;双侧颞上回激活;左侧顶上小叶激活;双侧小脑半球,枕叶,双侧梭状回,左侧角回激活。统计学有阳性意义的脑区包括:左侧Broca周边脑区(BA46区,BA10区)及右侧Broca区;②病灶位于左侧Broca区,并累及左额背外侧区或额中回的灰质,激活脑区如下:右侧Broca区无或少量激活,无统计学意义;肿瘤周边脑区:BA46,BA47,BA10区出现不同程度的代偿激活;右侧额中回及右侧额叶背外侧激活;双侧颞上回激活;左侧顶上小叶激活;双侧小脑半球,枕叶激活,统计学有阳性意义的脑区主要为左侧Broca周边脑区:BA46,BA47,BA10区等。结论脑肿瘤所致运动性失语,脑内代偿方式因位置不同而有差异。     

急性期脑梗死引起的运动性失语的功能磁共振研究

目的:探讨急性脑梗死引起的运动性失语脑内代偿情况。方法:急性脑梗死患者8例,男女比例1.3:1,平均44.5岁;正常健康志愿者20人,男10例,女10例,平均38.5岁,均为右利手。检查者均完成图片命名任务。AFNI软件处理实验数据。统计分析采用SPSS12.0分析软件。同一感兴奋区(ROI)比较采用两样本t检验或非参数统计:Mann-Whitney test。结果:患者组因病灶位置不同分为两组:①病灶位于左侧岛叶及左侧脑室旁白质5例。激活脑区如下:右侧Broca区,右侧BA10区,左侧角回,左侧顶上小叶,辅助运动区等。其中右侧Broca区激活强度和体素具有统计学意义,P0.05;②病灶位于左侧额下回(Broca区)3例。激活脑区如下:左侧BA46区,右侧顶上小叶,右侧额中回,左侧角回,辅助运动区等。正常对照组激活脑区:双侧岛叶,双侧额下回(Broca区,以左侧为著);双侧额中回,双侧额叶背外侧区,双侧顶上小叶,双侧颞上回,辅助运动区,双侧梭状回等激活。结论:急性脑梗死所致运动性失语,脑内代偿方式因位置不同而有差异。     

盘状半月板的四肢MR成像价值

目的：评价低场强四肢MR诊断盘状半月板的应用价值。方法：回顾分析经关节镜或手术证实为盘状半月板的20例患者的低场强四肢专用MR图像，对冠状位半月板测量。结果：均为外侧半月板。矢状位，半月板前、后角相连均超过三个层面，冠状位，半月板体部最窄处宽度超过15mm。结论：四肢专用MR矢、冠状位可准确的诊断盘状半月板。     

基于CT的DESH量表评分在特发性正常压力脑积水中的应用

【摘要】目的：探讨基于CT的DESH量表评分在特发性正常压力脑积水中的应用价值。方法：回顾性分析29例疑似iNPH患者临床及影像学资料,所有患者治疗前均行头颅CT及MR检查。分别对样本的头颅CT及MR图像进行DESH量表评分,比较CT与MR的DESH量表各参数的一致性,包括侧脑室扩大指数（Evans'' index,EI）、侧裂池扩大、大脑凸面挤压效应、胼胝体角（CA）及局部脑沟扩张的评分。结果：iNPH患者CT与MR的DESH量表各评分参数组内相关系数如下：ICCEI为0.928,ICC侧脑室评分为0.905,ICCCA为0.855,ICCCA评分为0.743,ICC侧裂池评分为0.983,ICC凸面挤压评分为0.984,ICC局部脑沟评分0.814,ICCDESH总分0.914。结论：CT与MR图像的DESH量表各参数评分具有良好的一致性,头颅薄层CT的三维重建图像可应用于iNPH患者DESH量表评分。     

The normal and abnormal genu of the corpus callosum: an evolutionary,embryologic, anatomic,and MR analysis.

PURPOSETo define the normal and abnormal genu of the corpus callosum by examining its evolution and embryology and by analyzing its normal and abnormal appearance on MR images.METHODSA reference line was drawn from the mamillary body through the anterior commissure and corpus callosum-the MAC line. This line was used to evaluate the genu in adult mammal brains, in human fetal brains, on MR images of 1800 patients with normal corpora callosi, and on MR images of 113 patients with callosal anomalies.RESULTSIn primates, increased frontal lobe size is associated with an anteriorly shifted genu. In human fetal development, the anterior body of the corpus callosum develops before the definitive genu. The normal human genu always projects in front of the MAC line. In none of the 113 patients with callosal anomalies was there only a normal genu.CONCLUSIONSThe human corpus callosum develops bidirectionally, not from front to back. The MAC line is a useful frame of reference to study the evolution and embryology of the genu and to distinguish the normal from the abnormal genu of the human corpus callosum.     

Limbic lobe embryology and anatomy: dissection and MR of the medial surface of the fetal cerebral hemisphere.

PURPOSETo facilitate understanding of limbic lobe anatomy by showing embryologic transformations of the medial surface of the cerebral hemisphere.METHODSBrains from fetal specimens ranging from 13 to 24 weeks of gestational age were dissected. Photographs were made of the medial surface of the cerebral hemisphere. MR images of different fetal specimens of similar age were made for comparison of MR anatomy with dissected material.RESULTSAt 13 weeks, the entire inner limbic arch of the hippocampal formation is visible on the medial surface of the cerebral hemisphere. The hippocampal sulcus extends from frontal lobe to temporal lobe. At 16 weeks, the outer neocortical limbic arch of the subcallosal area, cingulate gyrus, and parahippocampus gyrus is present. Growth of the corpus callosum is associated with reduction in size of the hippocampal formation in the frontal lobe. The sulcus of the corpus callosum is the remnant of the anterior part of the hippocampal sulcus. At 18 weeks, growth of the parahippocampal gyrus begins to conceal the hippocampal formation. The supracallosal gyrus (indusium griseum), hidden from view by the corpus callosum, and the paraterminal gyrus are remnants of the previously larger hippocampal formation.CONCLUSIONSAnalysis of fetal specimens in different developmental stages with dissection and MR provides insight into embryologic transformations responsible for the complex anatomy of the limbic lobe.     

The lamina rostralis: modification of concepts concerning the anatomy,embryology, and MR appearance of the rostrum of the corpus callosum.

PURPOSETo study the anatomy and embryology of the lamina rostralis, and to determine whether the rostrum is, as frequently stated, the last section of the corpus callosum to develop.METHODSThe rostrum was analyzed in dissected adult brains and on MR studies in 300 patients with a normal corpus callosum and in 84 patients with a hypogenetic corpus callosum. MR images of intact fetuses and photographs of dissected fetal and adult vertebrate brains were also analyzed.RESULTSThe rostrum extends from the genu to the upper end of the lamina terminalis and consists of two sections: a thick beaked segment and the thin lamina rostralis, which blends posteriorly with the lamina terminalis. During fetal development the lamina rostralis changes from a semivertical to a semihorizontal orientation. Many hypogenetic corpora callosi have a semivertical lamina rostralis. A rudimentary beaked segment can be present without a normal genu.CONCLUSIONSThe rostrum is not the last segment of the corpus callosum to develop. Rather, the lamina rostralis segment of the fetal rostrum is already present before the genu and splenium develop. Additionally, the beaked segment of the rostrum develops concurrently with maturation of the genu.     

Diffusion anisotropy in the corpus callosum

BACKGROUND AND PURPOSE: The corpus callosum is a heterogeneous white-matter tract that connects the cerebral hemispheres. The purpose of this investigation was to study its microstructural architecture in normal human adult brains by using diffusion tensor imaging (DTI). METHODS: Two hundred consecutive patients referred for brain MR imaging underwent additional DTI with a high gradient field strength applied in six directions. Forty-two patients met the following inclusion criteria: 1) normal brain and 2) age greater than 18 years. Anisotropy maps were generated, and regions of interest were drawn around specified regions within the corpus callosum. Results were stratified by sex and age. In addition, available histologic specimens of the corpus callosum from cadaver brains were analyzed with conventional and specialized vascular staining. RESULTS: Anisotropy values in the various regions of the corpus callosum differed significantly. Average values of the anisotropy index for the genu, body, and splenium of the corpus callosum were 0.400, 0.456, and 0.539, respectively. The differences between these values are statistically significant (P <.01). Increased anisotropy was present in posterior areas in both sexes and in all three age groups examined. CONCLUSION: The results of this investigation show a statistically significant increase in anisotropy of the corpus callosum in its more posterior portions compared with its more anterior portions across sex and age groups. Although the microstructural etiology for this apparent increase in anisotropy is unclear, a number of possible mechanisms are presented.     

Cranial MR imaging of sequelae of prefrontal lobotomy

BACKGROUND AND PURPOSE: Although prefrontal lobotomy is an obsolete treatment for schizophrenia, we still encounter patients who have undergone this procedure. The purpose of this study was to describe the MR imaging findings of sequelae of prefrontal lobotomy. METHODS: We retrospectively reviewed cranial MR images of eight patients with schizophrenia who underwent prefrontal lobotomy approximately 50 years previously. RESULTS: In all patients, a bilateral cavitary lesion with a thick wall was found in the frontal white matter. The genu of the corpus callosum was mildly to markedly atrophic. The size and location of the cavity and the degree of callosal atrophy were correlated. CONCLUSION: MR imaging is useful for the diagnosis of sequelae of prefrontal lobotomy, including cavitary lesions with dense walls of gliosis and secondary degeneration of the genu of the corpus callosum.     

Regional brain atrophy evolves differently in patients with multiple sclerosis according to clinical phenotype

BACKGROUND AND PURPOSE: Progressive brain atrophy is a well-known feature of multiple sclerosis (MS). We characterized the spatial evolution of atrophy in different MS phenotypes. METHODS: Dual-echo and T1-weighted MR images were obtained in 70 patients with MS and 10 healthy control subjects at entry and after 15 months. Within-group changes in regional atrophy were assessed by applying Structural Image Evaluation Using Normalization of Atrophy software and statistical parametric mapping analysis. Reported differences are for P <.001. RESULTS: During follow-up, patients with relapsing-remitting MS (RRMS) differences significant atrophy around the ventricular system; pericerebellar spaces; cerebellar tentorium; putamen; corpus callosum; cingulate sulcus; hippocampus; parieto-occipital fissure; lateral fissure; and frontal, parietal, temporal, and occipital cortex. Patients with secondary progressive MS developed significant atrophy of the cingulate sulcus; pulvinar; caudate nucleus; anterior orbital gyrus; mammillary body; fourth ventricle; and regions of frontal, parietal, temporal, and occipital cortex. Patients with primary progressive MS developed significant atrophy of the bilateral central sulcus; caudate nucleus; prepontine and quadrigeminal cisterns; lateral ventricle; and regions of frontal, parietal, temporal, and occipital cortex. In all phenotypes, the development of atrophy in some regions was significantly correlated with the accumulation of T2- and T1-visible lesions and clinical disability (r = -0.57 to -0.86). CONCLUSION: In MS, brain atrophy develops involving different structures in the different phenotypes. While ventricular enlargement is predominant in RRMS, cortical atrophy seems to be more important in the progressive forms. Measures of regional brain atrophy were significantly correlated with disability, suggesting that this approach is promising for bridging the gap between clinical and MR imaging findings in MS.     

A study on restriction of the areas working in speech function--application of multivariate analysis of aphasia test data and of lesions on CT images, by composing a "restricted-aphasia-lesion-map"

Computed tomography (CT) gave a large contribution to morphological analysis of the aphasia syndromes. The aphasia problems are, however, still controversial and have many unresolved issues, even from a morphological point of view. In most cases with cerebral vascular lesion causing speech dysfunction, we are able to define an extent of density change on CT images. But its extent seems to be often not consistent with the area supposed to be deranged in functional work-up of speech. CT appearance of some areas may be little changed or normal when those areas are to be in poor condition in their functional maintenance. This may be due to such a vascular supply which permits brain tissues to be sustained but which does not work for their function to be normally performed. From 642 cases with cerebral vascular lesion we reviewed CT images of 382 cases: 171 cases having a lesion in the left hemisphere and 46 of them showing aphasia syndrome; 151, a lesion in the right hemisphere alone and 3, aphasic; and 60 cases having lesions on both sides and 7 showing aphasia syndrome. First, we determined anatomically the extent of CT change in 102 cases, all right-handed, with a lesion in the left hemisphere. The extents were piled and made up to a "non-aphasia-lesion-map". This map was used for eliminating those areas as not working in speech function. The other map of the areas was made out of CT images of aphasia cases (33 cases including one agraphia). The latter map was put upon the "non-aphasia-lesion-map", so that the very area working in speech function could be more restricted. The third map, "restricted-aphasia-lesion-map" demonstrated those areas related to speech function: (1) the region limited around the three rami in the Sylvian fissure (Broca A); (2) the inferior frontal gyrus and the posterior aspect of the middle frontal gyrus (Broca B); (3) the inferior aspect of the cortex and subcortex of the Reil's island; (4) most of the middle temporal gyrus, the posterior third of the superior temporal gyrus, a large portion of the supramarginal gyrus and a part of the limbic system; (5) a large portion of the limbic system; (6) the anterior aspect of the superior frontal gyrus; and (7) the corpus callosum. The Standard Language Test for Aphasia (SLTA) was applied for 33 cases of aphasia.(ABSTRACT TRUNCATED AT 400 WORDS)     

2个CADASIL患者的弥散张量成像与20例正常人的比较

目的　分析2例CADASIL患者的MR特点及弥散张量指标的变化。方法　收集2例通过病理和基因检查确诊为CA DASIL的先证者的临床资料,对其进行常规MR扫描和弥散张量成像,将弥散张量成像的指标与20例正常志愿者的指标进行比较。结果　2例CADASIL患者的MR主要表现为双侧额顶叶白质内多发腔梗、脱髓鞘改变和双侧颞叶前部白质脱髓鞘。1例患者双侧外囊、内囊后肢、胼胝体膝部和压部的部分各向异性(FA)值均小于正常组的平均值减去2倍标准差,另1例患者左侧外囊的FA值小于对照组的平均值减去2倍标准差。结论　常规MR表现和弥散张量成像指标的测量均反映了CADASIL患者中存在严重的白质病变。     

Variation of perisylvian and calcarine anatomic landmarks within stereotaxic proportional coordinates

This investigation describes the variability in location of functionally important persylvian landmarks and of the calcarine sulcus within the Talairach stereotaxic grid, a system frequently used for cortical localization in functional images. Twenty healthy volunteers (40 hemispheres) had MR imaging under stereotaxic conditions. Outlines of the following structures were directly identified on sagittal 5-mm MR sections and marked on individual proportional grid overlays: inferior central sulcus, inferior precentral sulcus, inferior postcentral sulcus, anterior ascending ramus and posterior rami of the sylvian fissure, superior temporal sulcus, and calcarine sulcus. Maximal variation zones for these landmarks were defined by superimposition of the standardized individual data on a standard stereotaxic grid. The sulcal variation zones measured 1.5-2.0 cm. The findings indicate that macroanatomic individuality in the cerebral surface cannot be accounted for adequately by proportional coordinates, and that this method does not allow precise definition of anatomically based regions of interest for functional imaging. Instead, MR mapping of the individual sulcus pattern should be used to generate brain templates.     

液体衰减反转恢复脉冲对DWI图像信噪比及ADC值的影响

目的:探讨液体衰减反转恢复(FLAIR)脉冲序列对扩散加权图像(DWI)信噪比及ADC值的影响.方法:17名健康志愿者在3.0T MRI上行常规轴位DWI和FIAIR-DWI扫描,分别测量两侧半卵圆区、扣带回、丘脑及胼胝体膝部和压部的ADC值及DWI信号强度,同时测量基底节层面的DWI信号强度作为噪声,计算以上5个部位DWI图像的信噪比.结果:扣带回和胼胝体压部的ADC值在施加FLAIR脉冲后显著下降,而半卵圆区、丘脑及胼胝体膝部在施加FLAIR脉冲前后无明显变化;5个部位的DWI图像信噪比在施加FLAIR脉冲后均显著下降(P＜0.01).结论:FLAIR显著提高了脑组织和脑脊液ADC值测量的准确性,但是也明显降低了DWI图像的信嗓比.