磁共振相位对比电影对蛛网膜囊肿与蛛网膜下腔扩大的鉴别诊断

目的：应用磁共振相位对比法,揭示脑与脑脊液运动的相互关系,以评价此方法对鉴别蛛网膜囊肿与蛛网膜下腔扩大的诊断价值。材料与方法：运用磁共振相位对比电影和流动分析软件,对１０例健康人脑与脑脊液运动规律相关性进行研究和１０例影像学疑蛛网膜囊肿或蛛网膜下腔扩大患者的脑脊液运动进行最化分析,绘出一个心动周期不同时相脑脊液流量贡线和时间、信号强度曲线,并进行分析比较。结果：脑脊液流动是由脑运动驱动引起,而脑运     

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。     

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。     

脑血液流动磁共振定量技术的流体力学实验研究

目的：通过建立适当的流体模型,评价磁共振相位对比电影法对流体定量测量的可行性及准确性。方法：用磁共振相位对比电影法测定模拟脑血液流动的管状模型稳态流动下流体信号强度。并与相应的速率进行相关性分析后分别得出相应的转换函数关系。运用该转换函数选择性测量稳态及脉冲流动下管腔内各点的流体速率,并与相应激光多普勒测速对比分析以验证其测量准确性。结果：流体信号强度与对应速率呈线性相关,相关系数为0.985;相应信号强度（Y）和流率（X）的转换函数为Y=-0．0908X^2＋24.176X-15.304。不同流量状况下重复测量后,比较两次测量信号强度结果差异无显著性意义（P〉0．05）。两次测量值与实际值比较,测量误差均≤10％。磁共振相位对比电影法与激光多普勒测速仪测量的流率比较．两组数据相关性良好（P〈0.01,r=0.933）。结论：磁共振相位对比电影法是一种有效的脑血流定量技术,选择适当的扫描参数、准确的图像后处理及转换函数是确保该方法测量准确性的基础。     

探讨症状性骶管囊肿囊液性状与介入治疗预后的关系

目的 探讨症状性骶管囊肿患者囊液性状与介入治疗预后的关系.方法 114例症状性骶管囊肿患者,均有腰骶部不适等症状,其中初发86例,复发28例.在DSA引导下经皮穿刺进入囊肿内,抽吸2～5 ml脑脊液送实验室检查.然后再注入少量非离子型对比剂使囊肿显影,判断囊肿与蛛网膜下腔是否相通,最后再采用双针法抽吸囊液.结果 造影显示114例患者中66例患者显示囊肿与蛛网膜下腔相通,48例患者显示囊肿与蛛网膜下腔不相通;初发患者中两组脑脊液糖、氯化物差异有统计学意义,复发患者中两组脑脊液糖、蛋白质、氯化物差异有统计学意义.脑脊液的单项、多项改变与患者的介入治疗预后差异有统计学意义.结论 骶管囊肿分为与蛛网膜下腔通和不通的两种类型.初发和复发患者相比,脑脊液性状发生变化.脑脊液多项改变以及脑脊液糖升高、氯化物降低与患者介入治疗预后相关.     

Dandy——Walker综合征1例

病例 女性14岁。间歇性抽搐12年．近一年来抽搐发作频繁。查体：神清，头颅增大，左侧上下肢肌力减退。患儿2岁外院CT拟诊：枕部蛛网膜囊肿，脑积水。2002年12月23日MRI示：小脑体积小，后颅凹巨大囊肿，并与枕大池、四脑室相通，桥脑小脑脚部分残存，胼胝体变薄，压部发育不全，天幕上抬竖起，双侧枕叶、部分顶叶缺如为囊肿占位；脑干稍受压前移，中脑导水管不窄小，与囊肿相通；第三脑室、右侧脑室扩大；鞍上池无特殊，中线结构无移似；枕预部颅板变薄，信号改变。诊断：Dandy Walker综合征。     

脊蛛网膜囊肿的临床及X线同预后的关系

本文报告6例硬膜外和9例硬膜内脊蛛网膜囊肿的临床和X 线表现。蛛网膜囊肿沿蛛网膜下腔纵向伸展,并常通过相应窄小的颈与蛛网膜下腔相通。由于压迫脊髓或神经根常常可引起神经系统症状,甚或引起邻近骨侵蚀,其诊断通常以脊髓造影     

骶椎脊膜囊肿的MRI评价

骶椎脊膜囊肿通常是偶然发现的,目前无明确的影象学标准确定其是否可引发临床症状。标准MRI可精确显示脊膜囊肿的位置和大小,脊椎内肿物在T_1加权象上为低信号强度,在T_2加权象上为高信号强度,类似脑脊液(CSF)的信号强度。传统上使用X线平片或CT的脊髓造影来确定蛛网膜下腔与脊膜囊肿相通的情况。现在可应用MRI的流空效应研究脊膜囊肿内的液体流动。作者回顾性地研究了19例24个MRI的图象上的骶椎脊膜囊肿的大小和与蛛网膜下腔相通情况,患者年龄25～79岁,     

局灶性脑皮层发育不良的MRI诊断

目的 研究局灶性脑皮层发育不良(focal cortical dysplasia,FCD)的MRI表现特点.资料与方法 回顾性分析23例经手术病理证实的FCD患者的MRI表现.常规行横断位、矢状位及垂直于海马长轴的斜冠状位扫描,获得T1 WI、T2WI及液体衰减反转恢复序列(FLAIR)图像.结果 23例FCD病灶均表现为一侧大脑半球内局限性病变.病灶区域皮质增厚18例,灰白质分界模糊20例,皮层下白质异常信号22例,脑回、脑沟形态异常14例,邻近蛛网膜下腔局限性扩大4例.T1WI、T2WI及FLAIR显示灰白质分界模糊分别为6例、20例及18例;皮层下白质异常信号分别为3例、16例及19例;脑回、脑沟形态异常分别为12例、10例及11例.结论 FCD的MRI表现为皮质增厚、灰白质分界模糊、皮层下白质异常信号、脑回、脑沟形态异常及邻近蛛网膜下腔局限性扩大.T2WI及FLAIR显示灰白质界限、白质内异常信号较T1WI敏感,T1WI显示脑回、脑沟形态有一定的价值.     

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.     

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.     

CSF flow studies of intracranial cysts and cyst-like lesions achieved using reversed fast imaging with steady-state precession MR sequences

BACKGROUND AND PURPOSE: Differentiating between intracranial cysts or cyst-like structures and communicating or noncommunicating cysts is often not possible with cranial CT or nonfunctional MR imaging. We evaluated a retrospective ECG-gated fast imaging with steady-state precession (PSIF) MR sequence with optional cine mode to differentiate cystic masses from enlarged CSF spaces and to determine the accuracy of detecting communication between cysts and neighboring CSF spaces. METHODS: Fourteen patients with intracranial cystic masses underwent CSF flow studies with an ungated and a retrospective ECG-gated cine-mode PSIF sequence in addition to spin-echo imaging. Findings were evaluated retrospectively by using a five-point rating scale and without knowledge of clinical or other imaging findings. Results were compared with intraoperative findings or with results of intrathecal contrast studies. RESULTS: Eighteen arachnoid cysts and one enlarged cisterna magna were diagnosed. Improved differentiation between cysts and enlarged CSF spaces was obtained with cine-mode PSIF imaging in six lesions (six patients). Increased diagnostic certainty as to communication between cysts and CSF spaces was obtained in 18 cysts (13 patients). Diagnoses were verified by membranectomy in five lesions, by CT cisternography in five lesions, and indirectly by shunting in one cystic lesion. In one case, MR diagnosis was not confirmed by CT cisternography. CONCLUSION: Cine-mode MR imaging with a retrospective ECG-gated flow-sensitive PSIF sequence contributed to the certainty of communication between arachnoid cysts and neighboring CSF spaces with an accuracy of 90%, using surgical findings or intrathecal contrast studies as reference. Differentiation between intracranial cysts and enlargement of CSF spaces and other cystic masses was improved in 25% of cases.     

MRI findings in meningeal cysts of the vertebral column

Meningeal cysts (MC) are rare extensions of the meninges and are diverticula of the spinal meningeal sac, nerve root sheath or arachnoid that contain cerebrospinal fluid (CSF). They communicate with the subarachnoid space (SAS). The aim of this study was to demonstrate the MRI findings and to emphasise the contribution of MRI to the diagnosis of this rare pathology. MRI findings were evaluated according to a new classification that divides MCs into extradural cysts without (type 1) or with (type 2) spinal nerve root fibres and intradural cysts (type 3). Because of its high contrast resolution MRI can distinguish the three types of MC. The use of the different levels of signal intensity of the cyst and CSF in T2-weighted images to distinguish communicating from non-communicating MCs is illustrated. This diagnostic sign exploitats the signal loss due to flow phenomena of CSF pulsations on ungated sequences to reveal the communication of the MC with the SAS. We recommend MRI as the most sensitive and specific modality for the study of MCs. Correspondence to: R. S. Pozzi-Mucelli     

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.     

颅内表皮样囊肿的CT诊断

目的:分析表皮样囊肿的CT表现并提高其诊断准确性。材料与方法:11例患者,其中,男性6例,女性5例,年龄介于25～65岁,均经采用GE1600C型扫描仪以OM为基线横断扫描,于平扫后行增强扫描。结果:11例患者的病灶均呈囊性低密度,其中,圆形病灶见于3例,扁平不规则形且境界欠清的病灶见于8例。后者中,1例的病灶位于枕大池,压迫四脑室并引起幕上脑积水。1例的病灶位于鞍上池及环池。其余患者的病灶均位于桥小脑角池且有沿蛛网膜下腔生长的趋势。结论:只要掌握表皮样囊肿的上述CT表现,便容易将其与蛛网膜囊肿,皮样囊肿,以及颅内其他囊性肿块相鉴别。     

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.     

evaluation of communication between intracranial arachnoid cysts and cisterns with phase-contrast cine MR imaging

BACKGROUND AND PURPOSE: The demonstration of communication between arachnoid cysts (ACs) and the adjacent subarachnoid space is a prerequisite for their proper management. CT cisternography (CTC) is the conventional method for functional evaluation of ACs. The sensitivity of MR imaging to CSF flow has been demonstrated, but reports of the clinical usefulness of MR CSF flow techniques in this application are limited. The purpose of our study was to prospectively evaluate the accuracy of MR CSF flow study as an alternative to CTC in this setting. METHODS: MR CSF flow study with retrospective ECG-gated 2D, fast low-angle shot, phase-contrast (PC), cine gradient-echo sequence was performed in 39 patients with an intracranial AC. Results were compared with intraoperative and CTC findings. RESULTS: PC cine MR imaging results were compatible with operative or CTC findings in 36 (92.3%) of 39 patients. Twenty-four cysts were noncommunicating, and 15 were communicating. Three cysts were evaluated as being noncommunicating on PC cine MR imaging (false-negative) but demonstrated contrast enhancement on CTC. No false-positive diagnoses occurred. All cysts regarded as being communicating on PC cine MR imaging were also found to be communicating on both confirmation methods. CONCLUSION: MR CSF flow imaging with a PC cine sequence can be incorporated in the imaging work-up of ACs. This is a reliable alternative to invasive CTC for the functional evaluation of ACs.