正常成人大脑胼胝体弥散张量纤维束成像研究

目的 :利用磁共振弥散张量纤维束成像技术 ,研究正常成人大脑胼胝体的形状和结构。方法 :分别对 1 0名正常志愿者 (男 5例 ,女 5例。年龄为 2 4～ 6 5岁 ,平均年龄 4 0 .9岁 )进行弥散张量成像 ,将所得数据输入个人计算机 ,应用日本东京大学附属医院放射科影像计算和分析实验室所研制的软件 :Volume one1 .5 6和diffusionTENSORVisualizer 1 .5 (dTV)进行大脑胼胝体纤维束成像。结果 :本研究成功的在活体显示大脑胼胝体的形状和结构 ,在彩色FA图矢状面上胼胝体呈半月形 ,在弥散张量纤维束图横断面上呈蜈蚣状。结论 :弥散张量纤维束成像可以显示正常人大脑胼胝体 ,为大脑白质纤维束的研究开辟了一新的广阔领域。     

放射学孤立综合征的MR扩散张量成像研究

目的 应用MR DTI技术研究放射学孤立综合征(RIS)患者在常规MRI上表现正常的脑白质(NAWM)是否存在异常.方法 收集RIS患者27例(RIS组),同时选取16名年龄和性别均与RIS组相匹配的常规头颅MR检查无明显异常的健康志愿者(正常对照组),2组患者均行头颅常规MRI及DTI横断面扫描.测量受试者胼胝体膝部、体前部、体后部、压部以及额叶白质、枕叶白质的各向异性分数(FA)值、平均扩散系数(MD)值.2组之间不同区域的FA值、MD值比较采用独立样本t检验,同一研究者的2次测量值采用类内相关系数(ICC)分析.结果 同一研究者2次测量各参数基本一致,ICC值为0.934 ～0.989,显示2次测量结果的一致性较好.RIS组胼胝体膝部、体前部、体后部的FA值分别为0.705±0.040、0.632±0.042、0.628±0.043,相比于正常对照组0.738±0.045、0.675±0.042、0.666±0.045,均显著减小,差异有统计学意义(t值分别为-3.526、4.487、-3.890,P值均＜0.01);RIS组胼胝体压部、额叶和枕叶白质的FA值与正常对照组比较,差异均无统计学意义(t值分别为-1.387、-0.683、-1.243,P值均＞0.05).RIS组胼胝体膝部、体前部、体后部的MD值分别为(0.891±0.038)、(0.839±0.047)、(0.833±0.039)×10-3 mm2/s,相比于正常对照组(0.874±0.035)、(0.794±0.031)、(0.792±0.057)×10-3 mm2/s,均显著增大,差异有统计学意义(t值分别为2.101、5.836、5.146,P值均＜0.01);胼胝体压部、额叶白质和枕叶白质的MD值2组间比较差异均无统计学意义(t值分别为1.671、1.702、1.624,P值均＞0.05).结论 应用DTI技术可检测到RIS患者的NAWM存在异常.     

急性单侧大脑中动脉供血区局灶性梗死患者胼胝体各向异性的MRI初步研究

目的:利用MR DWI技术探讨单侧大脑中动脉供血区急性脑梗死时胼胝体各部分各向异性可能存在的变化。方法:连续选取病灶位于单侧大脑中动脉供血区的急性脑梗死患者66例(分为4组)及同期行MRI检查且年龄、性别与病变组匹配的66例40岁以上健康成人作为对照组。应用SSEPI序列行正中矢状面DTI扫描,在FA图上分别测量胼胝体膝部、体部前1/3处、体部中部、体部后1/3处及压部的FA值并进行统计学分析。结果:胼胝体体部前1/3处、体部中部及体部后1/3处的FA值均为正常组大于梗死组,胼胝体体部前1/3处及体部后1/3处的FA值正常组(分别为0.698±0.054和0.769±0.049)与梗死组(分别为0.665±0.049和0.653±0.078)之间差异存在统计学意义(t值为2.697和7.381,P<0.05)。胼胝体膝部及压部FA值均为梗死组(分别为0.780±0.082和0.772±0.049)大于正常组(分别为0.723±0.061和0.748±0.049),且两组之间差异有统计学意义(t值为-3.28和-2.08,P<0.05)。结论:单侧大脑中动脉供血区发生急性梗死时,连接双侧脑半球相应部位的胼胝体体部各向异性值减低,非承担这些脑叶间相互连接功能的膝部及压部各向异性值增高。     

Acquired lesions of the corpus callosum: MR imaging

In this pictorial review, we illustrate acquired diseases or conditions of the corpus callosum that may be found by magnetic resonance (MR) imaging of the brain, including infarction, bleeding, diffuse axonal injury, multiple sclerosis, acute disseminated encephalomyelitis, Marchiafava-Bignami disease, glioblastoma, gliomatosis cerebri, lymphoma, metastasis, germinoma, infections, metabolic diseases, transient splenial lesion, dilated Virchow-Robin spaces, wallerian degeneration after hemispheric damage and focal splenial gliosis. MR imaging is useful for the detection and differential diagnosis of corpus callosal lesions. Due to the anatomical shape and location of the corpus callosum, both coronal and sagittal fluid-attenuated inversion recovery images are most useful for visualizing lesions of this structure.     

Diffusion tensor analysis of corpus callosum in progressive supranuclear palsy

Introduction  Progressive supranuclear palsy (PSP) is a neurodegenerative disease featuring parkinsonism, supranuclear ophthalmoplegia, dysphagia, and frontal lobe dysfunction. The corpus callosum which consists of many commissure fibers probably reflects cerebral cortical function. Several previous reports showed atrophy or diffusion abnormalities of anterior corpus callosum in PSP patients, but partitioning method used in these studies was based on data obtained in nonhuman primates. In this study, we performed a diffusion tensor analysis using a new partitioning method for the human corpus callosum. Methods  Seven consecutive patients with PSP were compared with 29 age-matched patients with Parkinson’s Disease (PD) and 19 age-matched healthy control subjects. All subjects underwent diffusion tensor magnetic resonance imaging, and the corpus callosum was partitioned into five areas on the mid-sagittal plane according to a recently established topography of human corpus callosum (CC1—prefrontal area, CC2—premotor and supplementary motor area, CC3—motor area, CC4—sensory area, CC5—parietal, temporal, and occipital area). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in each area and differences between groups were analyzed. Results  In the PSP group, FA values were significantly decreased in CC1 and CC2, and ADC values were significantly increased in CC1 and CC2. Receiver operating characteristic analysis showed excellent reliability of FA and ADC analyses of CC1 for differentiating PSP from PD. Conclusion  The anterior corpus callosum corresponding to the prefrontal, premotor, and supplementary motor cortices is affected in PSP patients. This analysis can be an additional test for further confirmation of the diagnosis of PSP.     

正常成人胼胝体磁共振轴位及矢状位DTI定量研究

目的:研究正常成人胼胝体磁共振轴位扩散张量成像(DTI)与矢状位DTI各向异性(FA)可能的差异,探讨2种测量方法的可靠性。方法:对68例健康志愿者分别行轴位和矢状位DTI扫描,年龄18～78岁。分别测量胼胝体膝部及压部的FA值。对相同部位的轴位和矢状位测量结果进行比较,并行相关性分析。结果:矢状位上测量的胼胝体膝部FA值大于轴位,且两者之间差异有统计学意义(t=-5.833,P<0.001)。胼胝体压部FA值在矢状位与轴位上差异无统计学意义(t=0.435,P>0.05)。结论:矢状位与轴位DTI测量的胼胝体膝部及压部FA值不同,矢状位DTI能研究胼胝体各个区域各向异性的变化。     

MR扩散张量成像在鉴别脑缺血性疾病与多发性硬化中的应用价值

目的 探讨MR扩散张量成像（DTI）在鉴别脑缺血性疾病与多发性硬化（MS）中的临床应用价值。方法 单侧颈内动脉狭窄程度≥70％所导致的脑缺血性疾病患者32例，临床确诊为复发缓解型MS患者18例，均行头颅MR常规及DTI横轴面扫描。测量这些患者胼胝体膝部、体前部、体后部、压部以及额叶白质、枕叶白质的各项异性分数（FA）值。结果 MS患者的FA值在胼胝体的体前部、体后部和压部分别为0．67±0．12、0．67±0．09、0．71±0．01，较脑缺血性疾病患者（分别为0．75±0．05、0．72±0．05、0．76±0．06）降低（t值分别为3．443、2．281、1．846，P值均〈0．01）；MS患者在胼胝体膝部、额叶白质和枕叶白质FA值分别为0．63±0．13、0．34±0．08、0．29±0．06，缺血性疾病患者分别为0．69±0．08、0．34±0．05、0．加±0．06，两者差异无统计学意义（t值分别为1．781、0．137、5．449，P值均〉0．05）。结论 DTI可以在活体无创性地对脑白质进行检测和评价，对鉴别脑缺血性疾病和MS有一定的临床应用价值。     

胼胝体肿瘤的影像学诊断

目的 探讨发生于胼胝体的不同类型肿瘤的影像学表现.方法 回顾性分析25例发生于胼胝体的不同类型的肿瘤.分析各种肿瘤在不同影像学检查方法下的表现特点.结果 低级别星形细胞瘤1例,间变性星形细胞瘤2例,胶质母细胞瘤7例,少突胶质细胞瘤1例,间变性少突星形细胞瘤1例,少突一星形细胞瘤1例,原发恶性淋巴瘤10例,转移瘤1例,脂肪瘤1例.肿瘤最大直径7 cm,最小0.5 cm.肿瘤实性部分T1WI为等或低信号,T2WI为等或稍高信号,部分肿瘤伴囊变坏死.脂肪瘤CT平扫为低密度,CT值-85 HU.增强扫描星形细胞瘤呈不均匀、环状或蝶翼状强化,恶性淋巴瘤呈明显实性或环状强化,胶质母细胞瘤和淋巴瘤多向脑室或邻近脑质浸润.结论 胼胝体肿瘤的影像学表现具有特征性,可为手术切除肿瘤提供指导作用.     

正常人胼胝体膝部及嘴部年龄与性别差异的DTI研究

目的:研究胼胝体膝部和嘴部的DTI参数ADC值、部分各项异性(FA)值及神经密度在年龄及性别方面的差异,并获取其随年龄增长的变化规律。方法:将247例正常人按照年龄段分为10组,行颅脑DTI,测量胼胝体膝部和嘴部ROI的ADC值、FA值及神经纤维数,并计算神经密度。结果:①男性胼胝体膝部和嘴部的ADC值随年龄增长的差异均具有统计学意义;女性则差异均无统计学意义。②男性及女性胼胝体膝部和嘴部的FA值随年龄增长差异均具有统计学意义,其随年龄增长的变化规律基本上符合升高—相对稳定—下降的趋势。③男性及女性的胼胝体膝部和嘴部神经密度随年龄增长差异均无统计学意义。④在>3～6岁组,女性胼胝体嘴部的ADC值显著高于男性(P<0.01);在40岁以上男性,胼胝体膝部的神经密度显著高于女性(P<0.01);胼胝体膝部的ADC值和FA值、胼胝体嘴部的FA值和神经密度在各个年龄段内的性别差异均无统计学意义。结论:①胼胝体膝部和嘴部的ADC值、FA值随年龄增长的变化规律可以反映胼胝体膝部和嘴部生长发育及老化的整个过程。②本研究所获得的胼胝体膝部和嘴部的ADC值、FA值及神经密度可作为以后进一步研究的参考。     

正常成人脑结构年龄相关性变化的扩散张量成像研究

目的应用扩散张量成像（diffusion tensor imaging，DTU定量测定正常成人脑的各向异性及平均扩散系数（average diffusion coefficient，DCavg）的变化，以反映脑显微结构随年龄增长的变化。方法对106例正常成人行DTI，测定脑不同解剖部位的部分各向异性（fraction alanisotropy，FA）、1-容积比（1-volumeratio，1-VR）、相对各向异性（relative anisotropy，RA）和DCavg，分别对各参数与年龄进行相关性分析，且进行各组间比较。结果胼胝体膝部（FA：r=-0．491，P=0．000；1-VR：r=-0．508，P=0．000，RA：r=-0．494，P=0．000；DCavg：r=0．263，P=0．006）、压部（FA：r=-0．569，P=0．000；1-VR：r=-0．531，P=0．000；RA：r=-0．535，P=0．000；DCavg：r=0．475，P=0．000）、半卵圆中心（FA：r=-0．562，P=0．000；1-VR：r=-0．588，P=0．000；RA：r=-0．561，P=0．000；DCavg：r=0．337，P=0．000）、丘脑（FA：r=-0．210，P=0．031；1-VR：r=-0．203，P=0．036：RA：r=-0．213，P=0．028；DCavg：r=0．354，P=0．000）等的FA、1-VR、RA与年龄呈负相关，其DCavg与年龄呈显著性正相关。而豆状核的FA、1-VR、RA及DCavg（FA：r=0．287，P=0．005；1-VR：r=0．290，P=0．003；RA：r=0．283，P=0．003；DCavg：r=0．325，P=0．001）均随年龄增长而增加。结论DTI可无创性反映随年龄的增长脑的显微结构发生的变化。     

胼胝体胶质细胞瘤的MRI诊断

目的:探讨胼胝体胶质细胞瘤的MRI表现,提高对胼胝体胶质细胞瘤的认识。方法:对2 4例胼胝体胶质细胞瘤的MRI资料进行回顾性分析,并与病理结果作对照。结果:胼胝体胶质细胞瘤累及嘴、膝部15例,体部6例,压部3例。病理类型为星形细胞瘤18例,少支胶质细胞瘤4例,脑神经胶质瘤病2例。MRI表现为T1WI低信号、T2 WI高信号,信号均匀或不均匀,伴有水肿及占位效应,Ⅲ～Ⅳ级肿瘤多伴有坏死、囊变和出血,增强扫描根据肿瘤病理类型的不同可出现不同程度的强化。少支胶质细胞瘤伴斑片状钙化为其特征,脑神经胶质瘤病表现为多部位侵犯。胼胝体胶质细胞瘤可侵犯两侧或一侧大脑半球,形成“蝴蝶征”或“半蝴蝶征”,此二种征象有助于定位诊断。结论:胼胝体胶质细胞瘤是颅内特殊部位的肿瘤,MRI对其诊断具有重要临床价值。     

FA阈值对磁共振弥散张量胼胝体纤维束重建的影响

目的探讨FA阈值对MR弥散张量胼胝体纤维束重建的影响,并寻求最佳阈值。方法 20名健康成年人,男10例,女10例,分别行脑部常规MRI和DTI扫描。对DTI原始数据进行处理:调节不同FA阈值进行胼胝体纤维束重建,获得FDi和FA等参数,并对所得数据进行统计分析。结果①0.05～0.40间,每0.05取一个值作为FA阈值:FA阈值取0.05与0.1、0.3和0.35以及0.35和0.40时测得的FDi值统计分析无明显差别;其余各组之间FDi值均有统计学差异;②在0.10～0.30之间每0.01取一个值作为FA阈值:每组FA阈值下测得的FDi值均与相邻若干组之间无统计学差别—无差别组数较多的主要集中在0.16～0.24之间,其中以0.20时达到高峰;③不同FA阈值下测得的FDi值与FA值存在线性相关(r=-0.918)。结论①正常胼胝体纤维束成像时,FA阈值小于0.1或大于0.3时,纤维追踪将出现假阳性或假阴性结果;而0.16～0.24为正常胼胝体纤维追踪的适合阈值,其中0.20可能为最佳阈值;②FDi值是DTT的一个重要参数,与FA值存在密切的相关性。     

胼胝体梗死的临床和影像学分析

目的:探讨胼胝体梗死的临床和影像学特点,提高对胼胝体梗死的认识。方法:对30例胼胝体梗死患者的临床和CT、MRI、MRA资料进行回顾性分析。结果:胼胝体梗死均为单侧,按范围可分腔隙性和弥漫性。腔隙性梗死灶位于胼胝体膝部6例,体部4例,压部14例,弥漫性梗死同时累及单侧胼胝体膝、体部5例,单侧膝、体、压部1例。CT表现为圆形、卵圆形或条带状低密度影,MRI表现为T1WI像呈低信号,T2WI及水抑制序列呈高信号,CT、MRI增强扫描后无或轻度不均匀强化。MRA对弥漫性梗死可显示供血动脉不规则狭窄或闭塞。结论:CT、MRI和MRA对胼胝体梗死的诊断有重要价值。     

胼胝体梗死的MRI分析

目的 :分析胼胝体梗死的MRI表现和特征。方法 :13例胼胝体梗死患者 ,9例有高血压病史 ,4例有糖尿病 ,而同时合并有高血压及糖尿病者 3例 ,13例均行MR检查。结果 :梗死发生于胼胝体膝部者 2例 ,体部 8例 ,其中 3例为胼胝体体部多发梗死 ,1例为膝部和体部多发病灶 ,3例发生于压部 ,大小为 0 .2cm× 0 .3cm～ 1.1cm× 4.0cm。不同程度的伴有底节区、丘脑、脑干等部位的梗死。MRI上 ,T1 加权像呈低信号 ,T2 加权像上表现为高信号 ,增强扫描病灶表现为不强化或轻度不均匀强化 ,Flair序列为高信号。结论 :MRI可有效、准确、全面地显示胼胝体梗死的大小、范围以及合并的其他部位的病灶。     

胼胝体病变分布特点的MRI分析

目的 :总结各类胼胝体病变的MRI影像分布特点。方法 :68例经证实并行MRI检查的各种胼胝体病变按是否仅局限在胼胝体 ,横轴面上胼胝体区病灶是否按中线分布 ,胼胝体病灶的前后位置 ,胼胝体外脑内病灶是否左右对称分别分组 ,分析各种病变分布上有无特点。结果 :① 68例病变中 17例局限于胼胝体 ,5 1例合并胼胝体外脑内病灶。②胼胝体区病灶 5 6例为中线分布 ,12例为偏侧分布。③ 7例脑轴索损伤 ( 7/11) ,6例肾上腺脑白质营养不良 ( 6/6) ,3例脂肪栓塞 ( 3 /3 ) ,4例海洛因脑病 ( 4/4 ) ,1例病毒性脑炎 ( 1/2 )累及胼胝体压部。 6例胶质母细胞瘤 ( 6/10 )累及胼胝体前部。④非局限组中 3 6例 ( 3 6/5 1)脑内病灶为对称和基本对称分布。结论 :各种胼胝体病变的影像分布有明显的特征性     

Hump-shaped corpus callosum

Developmental anomalies of the corpus callosum are agenesis, hypogenesis, or hypoplasia. In this case, a hump-shaped anomaly was present in the body of the corpus callosum. The rostrum, genu, and splenium of the corpus callosum were normal. In addition, a split was present within this hump, connecting the lateral ventricles. No additional anomalies were present. This type of anomaly has not been previously reported in the literature.     

Classification of acquired lesions of the corpus callosum with MRI

MRI has facilitated diagnostic assessment of the corpus callosum. Diagnostic classification of solitary or multiple lesions of the corpus callosum has not attracted much attention, although signal abnormalities are not uncommon. Our aim was to identify characteristic imaging features of lesions frequently encountered in practice. We reviewed the case histories of 59 patients with lesions shown on MRI. The nature of the lesions was based on clinical features and/or long term follow-up (ischaemic 20, Virchow-Robin spaces 3, diffuse axonal injury 7, multiple sclerosis 11, hydrocephalus 5, acute disseminated encephalomyelitis 5, Marchiafava-Bignami disease 4, lymphoma 2, glioblastoma hamartoma each 1). The location in the sagittal plane, the relationship to the borders of the corpus callosum and midline and the size were documented. The 20 ischaemic lesions were asymmetrical but adjacent to the midline; the latter was involved in new or large lesions. Diffuse axonal injury commonly resulted in large lesions, which tended to be asymmetrical; the midline and borders of the corpus callosum were always involved. Lesions in MS were small, at the lower border of the corpus callosum next to the septum pellucidum, and crossed the midline asymmetrically. Acute disseminated encephalomyelitis and the other perivenous inflammatory diseases caused relatively large, asymmetrical lesions. Hydrocephalus resulted in lesions of the upper part of the corpus callosum, and mostly in its posterior two thirds; they were found in the midline. Lesions in Marchiafava-Bignami disease were large, often symmetrically in the midline in the splenium and did not reach the edge of the corpus callosum. Received: 15 October 1999 Accepted: 15 April 2000     

可逆性胼胝体压部病变综合征的磁共振成像诊断及预后评估

目的探讨可逆性胼胝体压部病变综合征的磁共振成像(MRI),分析其预后。方法回顾性分析2014年1月至2017年12月经我院诊断的50例可逆性胼胝体压部病变综合征的MRI影像学资料,分析患者的影像学特征。结果MRI诊断表现胼胝体压部孤立性,圆形或弧形,少数为斑片状,边界清晰。4例T1WI信号改变不明显,其余患者T1WI呈等或稍低信号,T2WI呈稍高信号,FLAIR为稍高信号,信号均匀,病变周围水肿和占位效应不明显,44例T1WI增强扫描病灶无明显强化特征;DWI呈明显高信号且表现扩散系数(ADC)呈低信号;5例行磁敏感加权成像(SWI)检查,4例行MRS检查,5例行MRA检查,结果未见异常特征;3例行扩散张量成像(DTI)检查显示各向异性分数(FA)值减低。45例复查MRI表现为胼胝体压部病变完全消失,无神经系统受累症状,预后效果好;3例DWI信号欠均匀,中央区见稍低信号,预后较差;1例随访发现患有严重神经系统后遗症,四肢无自主运动,长期卧床,预后不良。结论MRI能为RESLES临床诊断提供重要依据,结合其临床症状,为临床诊治提供重要参考依据,一般预后良好。     

The corpus callosum in communicating and noncommunicating hydrocephalus

To investigate morphological changes in the corpus callosum in hydrocephalus and to correlate them with clinical findings we studied sagittal T2^*-weighted cine MR images of 163 patients with hydrocephalus. The height, length and cross-sectional area of the corpus callosum were measured and related to the type of cerebrospinal fluid flow anomaly and to clinical features, especially dementia. With expansion of the lateral ventricles the corpus callosum showed mainly elevation of its body and, to a lesser degree, increase in length. Upward bowing was more pronounced in noncommunicating than in communicating hydrocephalus. Dorsal impingement on the corpus callosum by the free edge of the falx correlated with the height of the corpus callosum. Cross-sectional area did not correlate with either height, length or impingement; it was, however, the strongest anatomical discriminator between demented and nondemented patients. The area of the corpus callosum was significantly smaller in patients with white matter disease. Our findings suggest that, due to its plasticity, the corpus callosum can to some degree resist distortion in hydrocephalus. Dementia, although statistically related to atrophy of the corpus callosum, is possibly more directly related to white matter disease.Dedicated to Prof. M. Nadjmi on the occasion of his sixty-fifth birthday     

胼胝体压部局灶性非占位性病变的MRI诊断与鉴别

目的:总结胼胝体压部(SCC)非占位性病变的MRI特点。方法:回顾性分析29例SCC非占位病变的MRI及临床特点。结果:脑白质病(n=13)中11例MRI呈弥漫均匀形SCC灶,2例为边缘薄带形SCC灶,脑内病灶均为均匀、连续、对称分布,4例MRI复查未见明显变化。水肿性病变(n=11)中10例MRI表现为SCC弥漫不均匀病灶、1例为居中类圆形病灶,颅内病灶呈跳跃不对称分布,5例MRI复查病灶消失。3例脑梗塞SCC及脑内病灶呈偏侧分布,脑内散在病灶以患侧较多。2例SCC出血,SCC病灶弥漫不均匀,并见脑室内出血。结论:SCC非占位病变的影像及临床特点有助于鉴别诊断及预后判断,海络因吸入性脑病(LHVI)中SCC病灶的形态能反映病变的程度和范围。