视神经磁共振成像方法研究

目的探讨视神经磁共振(MRI)成像最佳方法及正常视神经MRI征象. 方法随机选择40例进行头部检查,无眼部疾患或视力障碍患者作为正常视神经研究对象.使用Philips ACS-NT15 1.5T超导型磁共振成像仪及正交头线圈.成像序列包括自旋回波T1加权成像(SE T1WI)及超快速自旋回波加或不加脂肪频谱饱和技术成像(TSE±SPIR T2WI).扫描方位包括与视神经平行轴位、斜矢状位及与视神经长轴垂直冠状位和标准冠状位. 结果视神经眶内段、管内段及视束粗细均匀.SE T1WI显示视神经较周围的蛛网膜下腔信号强度稍高,T2WI显示视神经呈相对低信号,与脑髓质信号相等,周围包绕高信号脑脊液.与视神经长轴平行的轴位及斜矢状位T1WI及T2WI均可显示视神经全貌,与视神经长轴垂直冠状位TSE+SPIR T2WI技术显示视神经信号均匀. 结论 MRI可以较好地显示视神经解剖,与视神经长轴垂直冠状位TSE+SPIR T2WI可以较好地显示信号特征.     

相位阵列线圈高分辨MRI显示肛管和肛周结构及其意义

目的：探讨应用体外相位阵列线圈高分辨MRI技术对肛管和肛周结构显示的可行性及其价值.方法：应用体外圆形极化相位阵列脊柱线圈对20例健康志愿者进行了高分辨MR扫描,扫描序列包括轴位T1WI,轴位、矢状和冠状平面T2WI及Gd-DTPA增强扫描的T1WI,轴位和冠状扫描平面分别垂直和平行于肛管的长轴.结果：肛管的粘膜、粘膜下层、肛门括约肌及会阴部结构如会阴体、会阴浅横肌、球海绵体肌、坐骨海绵体肌等在T2WI上均可清楚显示.男性和女性的肛管结构存在差异,女性外括约肌的前部明显短于后部,会阴体较男性大,而男性的球海绵体肌较女性厚.结论：体外相位阵列线圈高分辨MRI技术可清楚显示肛管和肛周结构的正常解剖,可为肛管区域病变的正确诊断和治疗提供较精确的解剖信息.     

正常踝关节的高场强磁共振成像扫描

目的:探讨正常踝关节高场强磁共振(MR)扫描技术.方法:6例人踝关节新鲜标本磁共振成像(MRI)扫描,应用两种不同的扫描条件分别行T1加权像(T1WI)、T2加权像(T2WI)、质子密度加权(PDW)、T2WI脉冲序列(SPAIR)冠状位、水平位,T2WI快速梯度回波(FFE)矢状位扫描.结果:在高场强的MRI运用小视野(FOV)(130 mm)、薄层扫描(2.0/1.0)、较大矩阵(410×510)及运用表面柔性线圈可提高踝关节MRI的分辨率.T1WI及PDW可提供最佳的解剖结构;提示T2WI能清晰地显示病变组织;提示SPAIR成像可良好地显示骨及软骨病变及区分脂肪组织内病变结构.结论:高场强MRI扫描是踝关节的理想影像学检查方法.     

MRI检查对宫颈癌的诊断价值研究

目的 探讨宫颈癌的MRI表现,评价MRI成像对宫颈癌诊断及判断周围侵犯的价值.方法 对经病理证实的20例宫颈癌患者(术前)行常规MRI及增强检查;行盆腔的轴面SET1WI,轴面及矢状面脂肪抑制(SPIR)T2WI,轴面弥散加权成像(DWI)及欧乃影(Gd-DTPA)增强后轴面、矢状面SET1WI扫描.在MRI图像上观察原发肿瘤的位置、信号特征及侵犯范围.结果 MRI常规序列及增强检查检出全部病例,准确率100％.宫颈癌的MRI表现颇具特征性,T2WI呈较高信号,T1WI呈等或低信号,DWI普通呈高信号,Gd-DTPA增强后T1WI可轻度强化.结论 MRI能多方位清晰显示宫颈癌瘤灶及侵犯范围与途径,明显优于其他影像学检查方法.     

基于CVH的肱二头肌长头腱滑轮系统薄层断面解剖与MRI对照研究

目的基于中国数字化人体(CVH)和MRI对照,观察肱二头肌长头腱(LBT)滑轮系统薄层断面解剖特点,为临床应用提供影像解剖学依据。方法 CVH肩关节解剖数据集5例斜冠状位、斜矢状位虚拟重建显示肱二头肌长头腱滑轮系统薄层断面解剖,并与20侧肩关节MRI平扫(T1WI),5侧肩关节MRI造影(MRA)对照,用Photoshop CS2软件观察LBT滑轮系统。结果LBT滑轮系统的主要结构喙肱韧带(CHL)、盂肱上韧带(SGHL)、肱二头肌长头腱(LBT)在MRI和CVH上显示清楚。CHL在T1WI斜矢状位显示最佳,SGHL在CVH横断面显示最佳,LBT在CVH上平行于LBT的斜冠状位显示最佳。LBT滑轮系统以斜矢状位CVH和MRA显示最佳,SGHL和CHL大致垂直,在LBT前方形成呈"T"分布的毗邻关系。结论 CVH和MRI显示LBT滑轮系统有很好互补性,以斜矢状位显示肱二头肌长头腱滑轮系统内部结构及毗邻关系为佳,为肩袖间隙疾病影像诊断提供了重要的识别标志。     

慢 性 胰 腺 炎 MR 诊断

目的探讨磁共振(MR)多种成像技术对慢性胰腺炎诊断的准确性及其临床应用价值。方法选择25例经手术病理、临床追踪和其他影像学方法证实的慢性胰腺炎MRI进行回顾性分析,其表现包括胰腺形态和体积改变、信号特征、动态增强扫描和MRCP所见。检查方法包括平扫冠状位T2WI,轴位T1WI,轴位T2WI,轴位T1WI FS(脂肪抑制)序列,磁共振胰胆管水成像(MRCP),动态增强前后的T1WI FS序列。结果胰腺体积弥漫性增大、T1WIFS病变区信号减低、动态增强扫描同步强化及串珠状扩张胰管穿透病变区是慢性胰腺炎的典型表现。结论MRI能更早发现慢性胰腺炎,显示胰管的改变和假性囊肿,对慢性胰腺炎诊断具有重要价值。     

MRI不同序列对骶髂关节软骨成像的比较

背景：平片及CT不能显示关节软骨的改变,磁共振虽可显示软骨,但常规序列软骨显像效果欠佳,因此若要提高MRI检出软骨病变的能力,序列的优化显得非常重要。 目的：比较骶髂关节常用磁共振成像序列,筛选适合骶髂关节软骨MRI最佳成像序列。 方法：对45健康志愿者分别行骶髂关节MRI自旋回波T1WI、T2WI、T1-flash-3d-water-cor、T2-me3d-cor和T2-me2d-cor和T1-se-cor-water-fil扫描,比较各个序列显示骶髂关节软骨的清晰度、内部信号变化及软骨表面缺损。 结果与结论：自旋回波T1WI和T2WI序列45均显示骶髂关节软骨为一条稍高信号带,关节间隙不清;梯度回波T1-se-cor-water-fil序列45均显示两侧关节面骨皮质与髂侧软骨、骶侧软骨及软骨间隙形成的5条平行线状结构;T2-me3d-cor、T1-flash-3D-water-cor-fil序列45例受检者关节软骨为一条明亮、清晰高信号,与周围骨皮质及骨髓分界非常清晰,但骶侧、髂侧软骨不能够区分。T2-me2d-cor序列 37例能显示髂侧、骶侧软骨及软骨间关节间隙,8例分辨不清;弥散成像序列仅部分层面能显示关节软骨,诸结构显示较模糊,信号强度对比不鲜明。结果说明,T1-se-cor-water-fil在关节软骨显示程度、内部信号变化和软骨表面缺损程度等方面明显优于其他序列。T1-flash-3d-water-cor、T2-me3d-cor和T2-me2d-cor对软骨表显示方面优于常规MRI序列,但不如T1-se-cor-water-fil。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程      

下丘脑核团的全脑MRI与断层解剖对比

目的 通过同例成人头颅标本磁共振成像与断层解剖图像的比较,明确全脑磁共振影像中下丘脑核团的形态、位置及信号特点。方法
选取6例成人头颅标本,分别行磁共振检查及断层标本制作,其中水平面、矢状面及冠状面各2例,对比观察同例标本下丘脑结构的影像解剖与断
层解剖特点。结果 穹隆及前连合在T1WI及T2WI中均显示为结构清晰的低信号结构,以T1WI为佳。通过穹隆及前连合等标志性结构定位,室旁核
在T1WI中呈等信号,边界清晰,在T2WI中呈等信号,边界清晰;乳头体核在T1WI中呈等信号,边界清晰,在T2WI中呈混杂信号,边界结构显示不
清;视上核在T1WI中呈等信号,与周围核团分界欠清,T2WI图像上显示为与周围灰质相同的等信号区。结论 磁共振临床常规头颅扫描序列可发
现下丘脑区部分核团。     

枕寰枢关节韧带断层与MR图像的对照研究

目的：为临床MRI诊断枕寰枢关节韧带损伤提供断层解剖学依据。方法：利用低温冰冻技术，将枕寰枢关节制成3．5mm厚的薄层断层标本，并与该区的磁共振图像相对照。结果：寰椎横韧带在横断位和矢状位，翼状韧带在斜冠状位和矢状位，齿突尖韧带在矢状位和斜冠状位能清楚观察各韧带的形态和毗邻关系。结论：在MRI上能清楚显示枕寰枢关节的各条韧带。     

磁共振场强及序列选择对金属植入物伪影大小影响探讨

目的比较不同场强不同序列伪影的差异。方法制作钛合金水模,分别在1.5 T和3.0 T MRI扫描仪上采用矢状位快速自旋回波(TSE)-T1、TSE-T2、TSE的短反转时间的反转恢复(STIR)的脂肪抑制、TSE的频率选择饱和法(FS)抑制、梯度回波序列(GRE)/快速小角度激发(FLASH)、扩散加权成像(DWI)等常用序列扫描。分析扫描得到图像伪影特点及进行伪影大小测量。结果GRE/FLASH序列图像和DWI图像伪影最大,FS抑制序列得到图像伪影比STIR序列图像伪影大,各序列伪影形状也有差别。在不同场强下相同类型序列扫描伪影也不同,高场强伪影明显大于低场强伪影。同一场强不同序列伪影大小不同,同一类型序列3.0 T MRI图像伪影比1.5 T MRI图像伪影要大,差异有统计学意义(P0.05)。结论可以通过场强选择、序列的选择来减少金属植入物磁共振扫描带来的伪影。     

嗅球和嗅束的断层解剖与MRI

目的：研究嗅球和嗅束的断面特点与MRI表现,为相关病变的影像学诊断和外科手术提供形态学依据。方法：选取国人成年尸头标本69例,经防腐和冷冻后,以电动断层带锯分别切制成连续横断层标本36例、矢状断层标本18例和冠状断层标本15例;采用SE序列,获取12例自愿者的头部1．5TMRI横、矢、冠状图像;利用3．0TMRI扫描仪,获取了10例自愿者的SE序列和3D-CISS序列头部断层图像;将上述连续断层标本和MRI图像相对照,观察、分析嗅球与嗅束的断面形态、MRI信号、位置及其毗邻关系等。结果：在冠状断面上,嗅球位于嗅束沟或直回与筛板之间,呈上方凹陷略扁的椭圆形;嗅束化于直同和嗅束沟下方,呈扁平的椭圆形。在矢状断面上,嗅球走行在颅前窝底直回下方,周围环绕以嗅池,其中上部嗅池较宽大。在横断面上,嗅束位于直回与眶回之间的嗅束沟内,视交叉的前外侧。MRI横断层、矢状断层和冠状断层图像均可显示嗅球、嗅束,其周围被嗅池环绕。结论：横断面、欠状断面和碰状断面均可清晰显示嗅球、嗅束的形态、位置和毗邻关系,其中以冠状断面为佳。     

Experimental study of fast and ultrafast T2-weighted imaging sequences using AMI-25 superparamagnetic iron oxide (SPIO)

The objective of this study was to evaluate fast and ultrafast T2-weighted images (T2WI), including echo planar imaging (EPI), using an AMI-25 agar phantom. Image quality for conventional spin echo (CSE) and turbo spin echo (TSE) was almost equivalent. In high-resolution TSE, image quality was highest due to the use of a 512 x 256 matrix. Half-Fourier single-shot turbo SE (HASTE) was associated with blurring of images, and turbo-gradient SE (TGSE) showed a deterioration of image quality. EPI also suffered from poor image quality because this method is very sensitive to magnetic field inhomogeneity. CSE showed good signal-to-noise ratio (S/N) and contrast ratio (CR), but also required the longest imaging times. Among the TSE sequences, TSE with a short echo train length (ETL) was superior in terms of S/N. The CR of EPI and fast low angle shot (FLASH) images were improved in proportion to the effective echo time (TE). At present, TSE is inferior to CSE in terms of S/N and CR. However, taking into consideration scanning time, TSE with a short ETL is thought to be suitable for routine examinations. Effective TE is an important factor in gradient echo (GRE) examinations.     

15～40周胎儿标本脊髓腰骶膨大发育的磁共振研究

目的 研究胎儿标本脊髓腰骶膨大（LSE）面积随胎龄变化的规律及MR表现.方法 收集胎龄15～40周的胎儿标本52例,以L2椎体为中心,行T12～ S1脊椎横轴位、矢状位和冠状位3.0T MRI T2WI扫描,观察脊髓LSE最大横断层面的前后径、左右径、面积及相应水平椎管面积,计算脊髓LSE最大横断层面的面积与相应水平椎管面积的比值,对上述测量结果和胎龄间的关系做回归分析.结果 在52例胎儿标本中,MRI T2WI横断面上脊髓清晰显示45例（86.54％）,显示不清7例（13.46％）;于胎龄15周在脊髓横断面显示脊髓信号和LSE信号,27周以前脊髓LSE呈“两环结构”,33周以后脊髓的双环样信号不明显.脊髓LSE最大横断层面的前后径、左右径及面积随胎龄的增加呈线性增长（P值均＜0.01）,脊髓LSE最大横断层面的面积与相应水平椎管面积的比值随胎龄的增加逐渐减小（P值均＜0.01）.结论 MR可清晰显示胎儿脊髓LSE在不同胎龄的发育表现及其与胎龄的变化规律.     

The human cerebral cortex on MRI: value of the coronal plane

The evaluation of different cortical areas of the cerebral cortex has been analyzed using MRI of 50 normal subjects without any neurological symptoms. This analysis has been made with different spin echo and gradient echo in T1 or T2 in three different planes: horizontal, sagittal and coronal. The most accurate plane to define important cortical areas such as Broca area, Wernicke area, temporal cortex at the level of the superior temporal sulcus, angular gyrus, supra marginal gyrus, hippocampal and parahippocampal cortices as well as that of the parieto or temporo –occipital areas is the coronal plane. Evidently it must be correlated with the other orthogonal planes. To be compared with the main Atlas of Neuroanatomy these sections must be perpendicular or parallel to the plane passing through the anterior and posterior commissures. MRI of patients with neurological disorders must have, as a routine, a series of MR sections performed in the coronal plane, as well as in horizontal and sagittal ones. The coronal plane is certainly the most precise to evaluate these areas involved in language, memory, visuo spatial or behavioral functions. It must be always compared with the rest of the neuroradiological examination and correlated with the clinical neurological signs.     

Neuroimaging and functional analyses for multiple sclerosis

For neuroimaging studies of multiple sclerosis(MS) lesions, magnetic resonance imaging (MRI) is most useful, while evoked potentials(EPs) are commonly used for functional analyses of neural damage due to MS. This review summarizes the MRI and EP findings in MS. MS lesions are visualized as high signal intensity lesions on T2-weighted images, proton density(PD)-weighted images, and fluid-attenuated inversion recovery(FLAIR) images, while such lesions demonstrate a low signal on T1-weighted images. New MS lesions are usually enhanced by gadolinium-DTPA on T1-weighted images, and the enhancement generally lasts 4 to 8 weeks. In Asian patients with MS, opticospinal MS(Asian-type MS) shows a significantly smaller numbers of brain MRI lesions than conventional MS(Western-type MS), while opticospinal MS shows a significantly higher frequency of the spinal cord atrophy on MRI than conventional MS. EPs are useful for detecting lesions located in certain portions of the central nervous system. MRI is not sensitive enough to detect small lesions in the optic nerves and spinal cord, whereas EPs are sensitive for optic nerve and spinal cord lesions. Thus, combined use of MRI and EPs is required for the diagnosis and the optimal monitoring of disease activity in MS.     

Ⅵ～Ⅷ对脑神经生物塑化薄片断层解剖与MRI对照研究

目的 :对展神经、面神经、前庭蜗神经进行塑化切片与MRI对照研究 ,获得正常影像和断层解剖资料。方法 :采用生物塑化技术制作脑神经横断位 8例、矢状位和冠状位各 1例薄层切片 ,同时采用FLASH -3D序列完成头颅标本及 3 0例正常人脑干MR扫描 ,以MPR技术完整显示展神经、面神经、前庭蜗神经脑池段全程。结果 :塑化薄片断层、标本和活体MR扫描 ,脑神经行程、解剖形态均有良好的对应关系 ,Dorello管和展神经海绵窦段在塑化切片上显示良好 ,MRI仅能部分显示。结论 :生物塑化薄层切片能够对脑神经及相关结构进行准确显示 ,是脑神经影像学研究的重要对比方法     

视神经和视交叉冠状断层解剖与MRI

目的：研究视神经和视交叉在冠状断面上的解剖特征与MRI表现,为相关疾病的影像诊断和外科手术提供解剖学资料。方法：选取15例成人尸头标本,以冷冻切片法切制成连续冠状断层标本;应用3．0TMRI扫描仪,获取10例志愿者头部的sE序列T1WI和T2WI图像;在上述断层标本和MRI图像上,观察分析冠状断面上视神经的形态、位置和毗邻关系。结果：视神经眶内段居于眶中心偏内上方,断面呈圆形,其周围有视神经鞘包绕,蛛网膜下隙清晰可见,眼动脉位于其上方;视神经管内段居于眶内上方,断面呈水平卵圆形,周围可见视神经鞘,蛛网膜下隙不明显,眼动脉位于其下方;视交叉冠状断面呈“一”字型,分隔上方的视隐窝和后下方的漏斗隐窝,其上方有大脑前动脉A1段,下方为灰结节和垂体柄。结论：冠状断面町以清楚显示视神经、视交叉的形态特点与毗邻关系。     

Ⅲ—Ⅴ对脑神经生物塑化薄片断层解剖与MRI对照研究

目的：对动眼神经、滑车神经、三叉神经进行塑化切片与MRI对照研究,获得正常影像和断层解剖资料。方法：采用生物塑化技术制作脑神经横断位8例、矢状位和冠状位各1例薄层切片,同时采用FLASH-3D序列完成头颅标本及30例正常人脑干MR扫描,以MPR技术完整显示动眼神经的三叉神经的脑池段全程。结果：塑化薄片断层、标本和活体MR扫描,脑神经行程、解剖形态均有良好的对应关系,滑车神经仅在塑化切片上显示。结论：生物塑化薄层切片能够对脑神经进行准确显示,是脑神经影像学研究的重要对比方法。     

MRI中T2WI高信号长度与急性颈脊髓损伤程度相关性研究

目的：探讨MRI中T2WI高信号长度与急性颈脊髓损伤程度的关系。方法：急性颈脊髓损伤患者37例,其中脊髓完全损伤19例,不完全损伤18例。全部病人均于伤后1～7天行MRI检查,于T2加权矢状位成像上选取高信号最长层面量取其长度,并分析其与颈脊髓损伤程度的关系。结果：急性颈脊髓损伤患者颈髓矢状面T2WI高信号长度,脊髓完全性损伤组明显高于不完全性损伤组（P〈0．01）。结论：MRI是临床诊断急性脊髓损害程度及评估其预后的良好的无创性检测方法。     

In the eye of experimental cerebral malaria

Cerebral malaria is the most severe complication of Plasmodium falciparum infection, accounting for 1 million deaths per year. We characterized the murine disease using in vivo magnetic resonance imaging (MRI) at 4.7 T, proving that ischemic edema is responsible for fatality. The aim of the present study was to identify early markers of experimental cerebral malaria using very high field conventional MRI (11.75 T). CBA/J mice infected with Plasmodium berghei ANKA were observed at an early stage of the disease, before the onset of detectable brain swelling and at the most acute stage of cerebral malaria. Herein, we report the first detection of damage to the optic and trigeminal nerves on T(2)-weighted MRI. The trigeminal nerves appeared hypointense, with significantly reduced diameter and cross-sectional area. The optic nerves were hypointense and often not visible. In addition, the internerve distance between the optic nerves was significantly and progressively reduced between the early and severest stages. Cranial nerve injury was the earliest anatomic hallmark of the disease, visible before brain edema became detectable. Thus, cranial nerve damage may manifest in neurologic signs, which may assist in the early recognition of cerebral malaria.