MR相位对比电影法在蛛网膜囊肿诊断中应用价值初探

目的：评价磁共振相位对比电影法在蛛网膜囊肿与蛛网膜下腔扩大及囊肿与邻近脑池是否相通的诊断价值。材料和方法：运用磁共振相位对比电影法和流动分析软件对21例影像学疑为蛛网膜囊肿或蛛网膜下腔扩大患者进行检查，并分析其相位幅度图像形态及博动情况,测定相应病变区在相位速度图上的搏动强度。结果：蛛网膜囊肿在相位幅度图上可不清楚显示囊肿与邻近脑池相分隔：同时可显示囊肿内搏动幅度。囊肿内反向流动信号及喷射信号改变，提示与邻近蛛网膜腔相通。而在四脑室扩大者，相位幅度图未见明显囊腔，可见与导水管相通。结论：磁共振相位对比电影法对显示不同部位颅内蛛网膜囊肿的形态、与邻近蛛网膜下腔结构鉴别及了解囊肿内搏动情况判断与邻近脑池是否交通有重要价值。     

磁共振相位对比法对脑与脑脊液运动的相关性研究

目的 应用磁共振相位对比法,揭示脑与脑脊液（ＣＳＦ）运动的相互关系,测定脑运动位移和脑脊液流量率。方法 运用磁共振相位对比电影和流动分析软件,对一组１０例健康人脑与脑脊液运动规律相关性进行研究。并测定在１个心动周期内脑实质各解剖区域的运动位移量和脑脊液流量率,绘制出动－静脉流量差,导水管、Ｃ２,３蛛网膜下腔、幕切迹区的脑脊液流量率、脑实质位移的时间－信号强度曲线,并进行分析。结果 脑运动大１个心动     

椎管内蛛网膜囊肿的影像诊断

目的分析椎管内蛛网膜囊肿的X线平片、CT及MRI表现,以提高对本病的认识。资料与方法回顾性分析29例经手术病理证实的椎管内蛛网膜囊肿影像特征并评价不同影像方法对该病的诊断价值,X线平片及MRI检查29例,9例行CT检查。结果髓外硬脊膜下及较小的硬脊膜外蛛网膜囊肿X线平片无异常表现。较大的硬脊膜外蛛网膜囊肿X线平片、CT及MRI均显示椎管及椎间孔呈对称性扩大。CT及MRI显示囊肿的密度或信号与脑脊液类似,并能显示伸出椎间孔外的硬脊膜外蛛网膜囊肿有“分叉征”。只有MRI能正确显示囊肿在椎管内的位置,并能显示与蛛网膜下腔相通的裂孔平面的囊肿腔内有“脑脊液喷射征”。结论MRI对大多数椎管内蛛网膜囊肿具有定位和定性诊断价值,并可判断硬脊膜外蛛网膜囊肿与蛛网膜下腔相通的裂孔位置。CT对该病具有一定诊断价值,X线平片诊断意义有限。     

五例蛛网膜囊肿脑电图分析

五例蛛网膜囊肿脑电图分析黎建民／￥￥特诊科主题词脑电描记术，蛛网膜，囊肿１病例报告例１男，１０岁。间断性头痛一年，加重一个月，有时出现“发呆”。查体正常。ＣＴ及ＭＲ示：左中颅窝可见一条形低密度影，边缘清，密度与脑脊液相近，诊断为蛛网膜囊肿。ＥＥＧ检查...     

急性蛛网膜下腔出血的低场强MRI诊断

目的探讨低场强ＭＲＩ诊断急性蛛网膜下腔出血的价值。材料与方法对８０例临床疑诊急性蛛网膜下腔出血的病人行ＭＲ检查,扫描机为ＡＳＭ—０１５ｐ,采用ＳＥ序列,参数Ｔ２ＷＩ≤ＴＲ２０００／ＴＥ１００ｍｓ,所有病例分别经腰穿、手术或治疗后复查证实,并与化脓性脑膜炎、结核性脑膜炎等脑脊液蛋白量增高的疾病进行了鉴别,与脑出血破入脑室或溢入蛛阿膜下腔者进行对照。结果本组病例在低场强ＭＲＩ条件下于病变区脑沟（裂池）等蛛网膜下腔Ｔ２ＷＩ均出现异常高亮脑脊液信号。探其原因为蛛网膜下腔出血可延长Ｔ２值。脑脊液蛋白含量高的其它疾病不出现异常高亮信号。结论低场强磁共振成像对急性蛛网膜下腔出血有较大的诊断价值。     

应用3.0TMR电影相位对比成像定量研究颈椎管内脑脊液腹侧和后外侧运动的区别

目的应用磁共振电影相位对比方法定量研究活体颈椎管内蛛网膜下腔脑脊液腹侧和后外侧运动的区别。资料与方法无任何颅内及椎管内病变的健康志愿者80例,应用GEsigna EXCITE3.0T HD磁共振扫描仪分别于颈2～7椎间盘水平行磁共振电影相位对比法扫描,获得每一个椎间盘水平一个心动周期内不同时相的脑脊液流速与流向,分别测量腹侧、右后侧及左后侧峰值流速、峰值流量。结果颈椎管内每一个水平腹侧峰值流速、峰值流量明显大于右后侧、左后侧峰值流速、峰值流量(P<0.05)。颈椎管内不同椎间盘水平的腹侧、右后侧及左后侧峰值流速、峰值流量没有显著性差异。结论应用磁共振相位对比法测量颈椎管内蛛网膜下腔脑脊液流速发现椎管内腹侧峰值流速、峰值流量明显大于右后侧、左后侧峰值流速、峰值流量。椎管内腹侧脑脊液循环动力明显大于两后外侧脑脊液循环动力。     

正常脑脊液流动的磁共振定性研究

目的探讨MRI 相位对比电影序列 （cine PC） 定性分析脑脊液流动的可能性,并运用该技术对正常志愿者进行分析.方法采用MRI cine PC序列对15名正常志愿者的脑室、脑池和颈椎管内蛛网膜下腔的脑脊液流动进行定性观察,并对心脏周期不同时段脑脊液流动方向的变化进行分析.结果 MRI cine PC序列可清楚地显示心脏周期各个时段各个脑室、脑池和脊髓蛛网膜下腔中脑脊液运动方向的变化.结论 MRI cine PC法是一种新型的无创性的检查手段,对脑脊液的流动有很强的敏感性,是一种很有前途的研究手段.     

蛛网膜下腔MR仿真内镜成像技术与临床意义

目的：探讨蛛网膜下腔磁共振仿真内镜（MRVE）成像技术，方法及临床价值。资料与方法。对临床要求常规序列检查的患者采用二维快速自旋回流重T2序列（2D HT－FSE）加行磁共振水成像（MRH），其中颅脑15例，脊椎11例，源影像数据传输至工作站利用导航软件行仿真内镜（VE）后处理重建成像。结果：在2D HT2－FSE图像上，脑脊液呈高信号亮色，明显高于邻近组织结构信号，采用“黑底白影”阈值方式、250－1100阈值重建获得了蛛网膜下腔VE图像。VE准确三维地展示了蛛网膜下腔及其邻近和穿行其间的脑、颅内腔、脊髓、椎管内腔、神经、血管与病变，对脑、脊髓表面结构，脑垂体、松果体和脑血管，部分颅神经起源、走行等显示颇佳，并可靠检出了小脑扁桃体上疝、听神经瘤、脊髓圆锥体位和椎管肿瘤、椎间盘突出等病变。结论：MRH是蛛网膜下腔VE有效的源影像技术，VE为评价蛛网膜下腔、脑、脊髓及其血管、神经正常解剖、变异与病变提供了一种安全、无创性、立体观察的崭新手段。     

椎管内蛛网膜囊肿的MRI诊断

目的探讨椎管内蛛网膜囊肿的MR I表现。方法搜集20例经MR I检查,手术病理证实的椎管内蛛网膜囊肿进行回顾性分析,其中男8例,女12例,行横断面及矢状面MR常规SE序列扫描,12例加做Gd-DTPA增强扫描。结果椎管内硬膜外蛛网膜囊肿5例,椎管内硬膜下蛛网膜囊肿6例,骶管内蛛网膜囊肿8例,神经鞘膜囊肿1例。囊肿信号与脑脊液信号相同,呈长T1、长T2信号,增强扫描无强化。结论MR I是诊断椎管内蛛网膜囊肿的最佳方法,平扫加增强扫描有助于诊断和鉴别诊断。     

颅内表皮样囊肿和蛛网膜囊肿的DWI鉴别诊断

目的:探讨磁共振扩散加权成像(DWI)对颅内表皮样囊肿和蛛网膜囊肿的鉴别诊断价值。方法:对20例颅内表皮样囊肿和15例颅内蛛网膜囊肿患者进行常规MRI及DWI检查,并获得表观扩散系数(ADC)图,分别测量病变区、健侧脑组织及健侧侧脑室内脑脊液的ADC值并进行统计学分析。结果:表皮样囊肿和蛛网膜囊肿在T1WI和T2WI上呈相同的信号改变;在DWI上表皮样囊肿呈高信号,而蛛网膜囊肿呈低信号;表皮样囊肿的ADC值[(10.197±0.329)×10-4mm2/s]明显低于蛛网膜囊肿[(30.098±1.510)×10-4mm2/s],差异有显著性意义(P<0.05)。结论:DWI对于表皮样囊肿与蛛网膜囊肿的鉴别诊断具有重要价值。     

Dynamic visualization of arachnoid adhesions in a patient with idiopathic syringomyelia using high‐resolution cine magnetic resonance imaging at 3T

A 39‐year‐old female patient with thoracic syringomyelia underwent routine magnetic resonance imaging (MRI) and 3 T MRI to investigate the value of retrospectively cardiac‐gated cine steady‐state free precession (SSFP) MRI in the preoperative and postoperative diagnosis of arachnoid membranes in the spinal subarachnoid space. Therefore, 3T MRI included sagittal and transverse retrospectively cardiac‐gated cine balanced fast‐field echo (balanced‐FFE) sequences both preoperatively and after microsurgical lysis of arachnoid adhesions and expansive duraplasty. Arachnoid membranes were detected and this result was correlated with intraoperative findings and the results of routine cardiac‐gated phase‐contrast cerebrospinal fluid (CSF) flow MRI. Retrospectively cardiac‐gated cine SSFP MRI enabled imaging of arachnoid membranes with high spatial resolution and sufficient contrast to delineate them from hyperintense CSF preoperatively and postoperatively. The images were largely unaffected by artifacts. Surgery confirmed the presence of arachnoid adhesions in the upper thoracic spine. Not all arachnoid membranes that were seen on cine balanced‐FFE sequences caused significant spinal CSF flow blockages in cardiac‐gated phase‐contrast CSF flow studies. In conclusion, retrospectively cardiac‐gated cine SSFP MRI may become a valuable tool for the preoperative detection of arachnoid adhesions and the postoperative evaluation of microsurgical adhesiolysis in patients with idiopathic syringomyelia. J. Magn. Reson. Imaging 2010. © 2010 Wiley‐Liss, Inc.     

磁共振脑脊液电影对四脑室囊虫病诊断意义的研究

目的：探讨磁共振脑脊液电影对四脑室囊虫病的诊断意义。材料与方法：经手术病理证实的四脑室囊虫病９例，回顾性分析其磁共振脑脊液电影表现。脑脊液电影采用头部正中矢状面，手指门控扫描技术。结果：（１）直接显示脑脊液（ＣＳＦ）循环通路及分布情况，四脑室内病灶均表现为ＣＳＦ的充盈缺损区。囊虫均为囊性，信号均、壁光整，壁可薄可厚。（２）ＣＳＦ流动为搏动性往复运动，以导水管区最明显。在心脏收缩期，导水管内的ＣＳＦ由三脑室流向四脑室，囊虫上方残余的四脑室腔扩张增大，舒张期缩小，顺应性良好。（３）四脑室囊虫存活期，边缘光整，ＣＳＦ于其上方前后分流呈杯口状，囊虫游离于四脑室内，并可滚动，其形态在一个心动周期内可有轻微变化；退变死亡期囊虫，周围室管膜出现炎性反应，并与囊虫壁粘连，ＣＳＦ循环受阻更明显。结论：磁共振不但能对四脑室囊虫病做出准确的定位、定性诊断，而且可通过脑脊液电影了解囊虫灶对ＣＳＦ循环的阻塞程度和方式，以及观察囊虫与室管膜是否有粘连，从而为选择治疗方案提供指导意义。     

Cerebrospinal fluid flow imaging by using phase-contrast MR technique

Cerebrospinal fluid (CSF) spaces include ventricles and cerebral and spinal subarachnoid spaces. CSF motion is a combined effect of CSF production rate and superimposed cardiac pulsations. Knowledge of CSF dynamics has benefited considerably from the development of phase-contrast (PC) MRI. There are several disorders such as communicating and non-communicating hydrocephalus, Chiari malformation, syringomyelic cyst and arachnoid cyst that can change the CSF dynamics. The aims of this pictorial review are to outline the PC MRI technique, CSF physiology and cerebrospinal space anatomy, to describe a group of congenital and acquired disorders that can alter the CSF dynamics, and to assess the use of PC MRI in the assessment of various central nervous system abnormalities.     

Flow dynamics of cerebrospinal fluid: assessment with phase-contrast velocity MR imaging performed with retrospective cardiac gating.

To visualize the flow of cerebrospinal fluid (CSF) throughout the ventricles and subarachnoid space, measure mean and maximum CSF velocities, and quantitate CSF flow through the aqueduct of Sylvius, magnetic resonance (MR) imaging was performed with a sagittal technique that is flow-sensitive in the craniocaudal direction (along the readout axis) and a high-resolution axial technique sensitive to through-plane flow in three healthy subjects and 19 patients with known or suspected disorders of the CSF circulation. In both techniques, retrospective cardiac gating was used to cover the complete cardiac cycle. The sagittal technique was superior in overall assessment of CSF flow dynamics, including the motion of adjacent brain parenchyma. The high-resolution axial technique provided an accurate measurement of the rate of CSF flow through the aqueduct; only this technique provided sufficient accuracy to enable distinction between normal and hyperdynamic CSF flow. It is concluded that assessment of CSF flow dynamics is a useful adjunct to routine MR imaging in communicating and obstructive hydrocephalus.     

脑脊液正常流动的MRI研究

 目的 探讨MRI相位对比序列(cine PC)研究和分析脑脊液流动的可能性,并运用该技术对正常志愿者进行分析.方法 采用MRI cine PC序列, 对正常志愿者进行分析,并测量中脑导水管上下丘之间的横断层面脑脊液的流动速度.结果 MRI cine PC序列可清楚地显示心脏周期各个时段各个脑室、脑池和脊髓蛛网膜下腔中脑脊液运动方向的变化,并能对脑脊液流速进行精确地测量.结论 MRI cine PC法是一种新型的无创性的检查手段,对脑脊液的流动有很强的敏感性,是一种很有前途的研究手段.     

Normal flow patterns of intracranial and spinal cerebrospinal fluid defined with phase-contrast cine MR imaging

A phase-contrast cine magnetic resonance (MR) imaging technique was used to study normal dynamics of cerebrospinal fluid (CSF) in 10 healthy volunteers and four patients with normal MR images. This pulse sequence yielded 16 quantitative flow-encoded images per cardiac cycle (peripheral gating). Flow encoding depicted craniocaudal flow as high signal intensity and caudo-cranial flow as low signal intensity. Sagittal and axial images of the head, cervical spine, and lumbar spine were obtained, and strategic sites were analyzed for quantitative CSF flow. The onset of CSF systole in the subarachnoid space was synchronous with the onset of systole in the carotid artery. CSF systole and diastole at the foramen of Monro and aqueduct were essentially simultaneous. The systolic and diastolic components were different in the subarachnoid space, where systole occupied approximately 40% and diastole 60% of the cardiac cycle, compared with the ventricular system, where they were equal. This difference results in systole in the intracranial and spinal subarachnoid spaces preceding that in the ventricular system; the same is true for diastole. The fourth ventricle and cisterna magna serve as mixing chambers. The high-velocity flow in the cervical spine and essentially no flow in the distal lumbar sac indicate that a portion of the capacitance necessary in this essentially closed system resides in the distal spinal canal.     

MR phase imaging and cerebrospinal fluid flow in the head and spine

Summary Motion of the cerebrospinal fluid (CSF) in and around the brain and spinal cord was examined in healthy subjects and in a number of patients with abnormalities of the CSF circulation. The pulsatile motion of the CSF was determined by spin echo phase (velocity) imaging, sometimes in combination with gradient echo phase contrast cine. Differences in flow patterns across CSF spaces were observed: flow reversal in the cerebellomedullary cistern and lumbar area relative to cervical CSF, and in the posterior versus the anterior subarachnoid space in the spinal canal. Flow communication was demonstrated in known communicating cysts or cavities. Differences in flow were also noted across spinal narrowing or block, and across the walls of a variety of cystic lesions in the brain and spinal cord. MR phase imaging of CSF flow provides pathophysiological information of potential clinical importance for the assessment of diseases affecting the CSF circulation.