MRI高分辨力黑水成像对交通性脑积水中脑导水管通畅性的诊断价值

目的 :通过高分辨力黑水序列判断交通性脑积水患者中脑导水管是否通畅。方法 :选择54例交通性脑积水患者,行矢状位黑水序列和轴位脑脊液相位对比电影(PC cine)序列。扫描结束后,由2位高年资医师行双盲法判读;先根据黑水CUBE T_2判断中脑导水管是否流通,根据图像特点诊断中脑导水管流通性。后使用PC cine序列测量中脑导水管处流速,并以此为中脑导水管通畅与否标准,与黑水CUBE T_2序列进行对照。比较交通性脑积水和正常对照组中脑导水管脑脊液流速和流量。结果:交通性脑积水患者中脑导水管流速和流量明显大于正常志愿者(均P0.05)。2名医师根据黑水序列诊断交通性脑积水患者中脑导水管畅通性比较差异无统计学意义(P=0.25)。ROC曲线下面积为0.956(95%CI 0.883~0.990),AUC0.9,说明对交通性脑积水的诊断价值较高。结论:MRI黑水序列无创、简便易行,能充分显示交通性脑积水患者脑脊液流动路线,可用于诊断交通性脑积水患者中脑导水管通畅性。     

交通性脑积水脑室分流前后的脑脊液MRI定量研究

目的运用MRI cine PC定量研究交通性脑积水脑室分流前后的脑脊液流动情况.材料和方法在1.5T GEHo rizon Signa磁共振机器上利用MRI cine PC程序,在以前实验所得的液体流速与信号强度关系公式的基础上,对16例交通性脑积水的中脑导水管、枕大孔和C2水平脑脊液流速、流量情况进行MRI cine PC检查(1.5TGE Horizon Signa),并对其中10例交通性脑积水脑室引流后的中脑导水管和枕大孔处脑脊液的流速和流量同样进行测量,并与术前进行比较.同时作为对照,对31例正常志愿者颅内中脑导水管、枕大孔和C2水平的脑脊液流速和流量进行测定.结果交通性脑积水中脑导水管水平脑脊液流速和流量明显增快,与正常者进行统计有明显差异(P＜0.05),向下峰速和向上峰速分别为47.57±16.71mm/s和44.48±19.22mm/s,向下流量及向上流量明显增大为3.142±1.055ml/s及3.143±1.055ml/s;脑脊液净流量为0±0.003ml/s.而枕大孔向下峰速和向上峰速分别为1.37±0.44mm/s和1.33±0.41mm/s,向下流量及向上流量分别为0.351±0.125ml/s及0.350±0.121ml/s;脑脊液净流量为0.001±0.007ml/s.C2水平脑脊液向下峰速和向上峰速分别为2.41±1.27mm/s和2.95±1.15mm/s,向下流量及向上流量分别为0.521±0.214ml/s和0.519±0.214ml/s;脑脊液净流量为0.002±0.003ml/s.其中10例交通性脑积水经VP手术前后对比分析,发现术后症状改善明显者中脑导水管脑脊液流速和向上、下的流量均较术前明显减少(P＜0.05).结论MRI cine PC对脑脊液(CSF)流动的研究具有非损伤性和对脑脊液流动敏感的特点,是一种优于其他方法的研究CSF流动的重要方法,同时对脑脊液循环障碍疾病的脑脊液流动情况也能定量测定,对VP分流前后的交通性脑积水的脑脊液流速、流量和方向的确定,对估计其术后效果具有重要意义.     

磁共振相位对比电影成像在脑积水诊断中的临床应用

目的评价磁共振相位对比电影成像（PC-MRI）技术在脑积水诊断中的临床应用价值。方法使用GE3.0 T磁共振扫描仪,采用PC-MRI程序检查,对我院收治的20例交通性脑积水及25例梗阻性脑积水患者及48名同期在我院体检的志愿者的中脑导水管水平脑脊液流速、流量进行检测,比较2组脑脊液相关力学数据基本情况。结果 交通性脑积水中脑导水管水平脑脊液在不同阶段所引起的反应存在着一定的差异,其中在收缩期与舒张期分别表现为向下、向上峰速,而且均大幅增加了其流量;梗阻性脑积水中脑导水管水平脑脊液在不同阶段所引起的反应也存在一定的差异,其中在收缩期与舒张期分别表现为向下、向上峰速,而且在流量方面都出现大幅降低的现象。相较于健康人进行统计有明显差异（P<0.05）,健康人（对照组）脑脊液流动曲线呈U形、倒U形,正弦波形,曲线光滑,而脑积水组脑脊液流动曲线呈锯齿状,无规则,或呈直线。结论 磁共振相位对比电影成像能无创检测脑脊液流速、流量和方向,可鉴别脑积水类型,为临床治疗提供方向。     

磁共振相位对比方法测量导水管脑脊液流量

目的 :探讨 0 .5TMR扫描系统测量导水管脑脊液 (CSF)流量的可行性、可靠性和精确性。方法 :对健康志愿者 8例、正常受检者 2 2例行导水管MR相位对比电影 (PCcine)序列扫描 ,用流动分析软件测量导水管脑脊液流量。结果 :正常人导水管CSF的峰速度 (PV)为 ( 7.987± 2 .95 7)cm /s ,平均速度 (ASV)为 ( 0 .3 0 3± 0 .2 46)cm/s ;导水管CSF搏动性流动与心动周期的关系为正弦波形。结论 :用磁共振相位对比方法测量导水管脑脊液流量 ,有助于对疾病状态下导水管CSF流量变化的分析     

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.     

MRI相位对比电影用于儿童脑积水行三脑室底造瘘的疗效评价

目的 了解脑积水患儿行神经内镜下三脑室底造瘘术后的MRI相位对比电影的表现,评价其用于术后疗效判断的价值.方法 12例脑积水患儿行三脑室底造瘘术前后均行MRI常规序列扫描及相位对比电影检查,评估中脑导水管及三脑室造瘘口的脑脊液流动情况,测量脑脊液流动动力学指标(峰值流速、流量及流动波形),比较其前后的差异.结果 12例脑积水患儿造瘘口脑脊液流动在一个心动周期内表现为双向运动,与正常导水管流动波形相似.其中三脑室造瘘术前7例梗阻性脑积水患儿中脑导水管脑脊液双向流动减弱或消失,表现为低动力学改变;5例交通性脑积水患儿三脑室底造瘘术前中脑导水管脑脊液双向流动明显加快,表现为高动力学改变.三脑室底造瘘术后中脑导水管脑脊液流动不规则,循环减慢.12例患儿术后幕上脑室均较术前缩小,其中8例分别于术后半年及术后1年复查见脑室进一步缩小.结论 MRI相位对比电影法为脑积水患儿行三脑室底造瘘术提供可靠的影像学观察手段,可以作为评价三脑室底造瘘术疗效的有效方法.     

正常中脑导水管脑脊液MR流速流量研究

目的探讨中脑导水管脑脊液(CSF)流速、流量测量正常值。方法应用Philips Intera Achieva 1.5TMR机对30例健康志愿者行导水管MR相位对比法CSF-QF序列扫描,用流动分析软件测量中脑导水管脑脊液速、流量。结果中脑导水管截面像素为13.73±3.59,导水管CSF的上峰速度为(6.40±1.85)cm/s,下峰速度为(7.88±3.04)cm/s,上峰流量为(0.12±0.05)ml/s,下峰流量为(0.15±0.07)ml/s,返流系数为(90.86±6.79)%,绝对流量为(0.07±0.05)ml/s,平均流速值为(0.01±0.18)cm/s。中脑导水管CSF搏动性流动与心动周期的关系为正弦波形。结论建立了Philips Intera Achieva 1.5T中脑导水管脑脊液流速、流量正常值。     

MR流量分析在脑脊液研究方面的应用

ＭＲ流量分析软件的应用为无创地研究脑脊液生理与病理提供了新的技术方法，通过测量颅内及颈段不同解剖部位（导水管，基底池，Ｃ２．３蛛网膜下腔）的脑脊液流量，发现脑脊液流量与脑膨胀有密切关系，而脑膨胀则被认为是在一个心动周期内颅内动脉充入与静脉流出量存在流量差所致，通过测量脑脊液流量，希望能够在临床上对脑脊液紊乱做出定量诊断。     

磁共振3D-TSE-DRIVE成像对中脑导水管梗阻的诊断

目的 探讨磁共振3DTSEDRIVE成像对中脑导水管梗阻的诊断价值.方法 幕上脑积水患者31例,应用Philips Achieva (1.5T)超导型MRI扫描仪,SENSENV16线圈,行中脑导水管3DTSEDRIVE成像检查、相位对比法脑脊液电影成像及脑脊液流速分析.结果 3DTSEDRIVE序列检出中脑导水管部分狭窄、粘连22例,导水管闭塞3例,导水管通畅6例.结论 3DTSEDRIVE成像可清晰显示中脑导水管细节,能显著提高中脑导水管梗阻的诊断准确率,可作为常规MRI检查的重要补充.     

脊髓病变病人的脑脊液流动MRI研究

目的：利用相位对比动力学MRI研究脊髓病变病人的脑脊液动力学。材料和方法：对脊椎侧凸病人20例，脊髓空洞症病人20例，Chiari畸形病人20例，脊髓肿瘤20例和无脊椎脊髓病变50例，采用Philips 1．5T超导型磁共振常规MRI检查后，行磁共振Qflow序列检查。测量部位选择C2—3椎间盘横断面，将检测数据传到Easyvison后处理工作站计算出流速和流量，并通过软件模拟出脑脊液流动的波形。结果：以50例无脊椎脊髓病变的脑脊液动力学为等动力学参照，发现脊椎侧凸病人和脊髓肿瘤的脑脊液动力学为高动力学，脊髓空洞症病人和Chiari畸形病人的脑脊液动力学为低动力学。结论：①无创伤性相位对比动力学MRI为研究脊髓病变病人的脑脊液流动提供可靠、稳定的技术方法；②脊髓空洞症脑脊液低动力学为临床脊髓空洞症做出定量的诊断，有进一步研究和推广应用的价值。     

Cerebrospinal fluid flow in children with normal and dilated ventricles studied by MR imaging

Purpose: To quantify the cerebrospinal fluid (CSF) dynamics in the aqueduct of children with normal and dilated ventricles using MR phase-contrast technique.Material and Methods: Eighteen patients (6 months to 17 years of age) with various neurological symptoms underwent routine brain MR imaging and CSF flow measurement in the aqueduct. Nine patients had normal ventricles, 5 had dilated ventricles and 4 had a ventriculoperitoneal shunt.Results: The CSF velocity and flow rates in the aqueduct in patients with normal and dilated ventricles showed marked inter-individual variation and clear overlap. In a patient with tight aqueductal stenosis and increased ventricular pressure, pronounced CSF flow in the aqueduct was measured. Absence of flow in another patient with aqueductal stenosis was detected. Measurable although low flow in the aqueduct in 4 patients with a ventriculoperitoneal shunt was found.Conclusion: Quantitative phase MR flow measurement in the aqueduct demonstrated aqueductal stenosis; these patients had either pronounced flow or no flow in the aqueduct.     

Fast multiphase MR imaging of aqueductal CSF flow: 1. Study of healthy subjects

Gradient-echo MR sequences are more sensitive to flow phenomena than spin-echo sequences are. We investigated aqueductal CSF flow by fast multiphase imaging. Fast multiphase imaging offers the opportunity to perform a dynamic study of fluid motion that is synchronous with the cardiac cycle. A section perpendicular to the cerebral aqueduct was imaged in 18 healthy volunteers. Serial, gated (every 50 msec from the ECG R wave), flow-compensated modulus images with 70 degrees-flip-angle excitation pulses were obtained with a single acquisition. The behavior vs time of CSF signal in the aqueduct was compared with that in the lateral ventricles. The former showed a peak at 0.47 +/- 0.1 fractions of a heart cycle after the R wave. No periodicity with the heart rate was observed for the ventricular CSF signal intensity. The mean CSF signal intensity in the aqueduct was found to range from about twice to three times that in the lateral ventricles over a cardiac cycle. Fast multiphase imaging is a sensitive and practical sequence for the MR investigation of aqueductal CSF flow. Its potential in patients with hydrocephalus is studied in a companion article.     

SPAMM, cine phase contrast imaging and fast spin-echo T2-weighted imaging in the study of intracranial cerebrospinal fluid (CSF) flow

AIM: To compare the qualitative assessment of cerebrospinal fluid (CSF) flow using a SPAMM (spatial modulation of magnetization) technique with cine phase contrast images (cine PC) and fast spin echo (FSE) T2-weighted images. MATERIALS AND METHODS: SPAMM, PC and T2-weighted sequences were performed on 22 occasions in 19 patients. Eleven of the studies were performed following a neuroendoscopic third ventriculostomy (NTV), and in these cases, the success of the NTV was determined by clinical follow-up. Two observers used consensus to grade the presence of CSF flow at nine different sites for each study. RESULTS: At 14 of the 178 matched sites, which could be assessed by both SPAMM and cine PC, SPAMM CSF flow grade was higher than that of cine PC. At a further 14/178 matched sites, the cine PC grade was higher than that of SPAMM. There was definite CSF flow at 113/182 (62%) of all the cine PC sites assessed, and 110/181 (61%) of all SPAMM sites assessed whilst 108/198 (54%) of FSE T2-weighted image sites demonstrated flow voids. Cine PC grades were higher than SPAMM at the cerebral aqueduct (P < 0.05, Wilcoxon sign rank test). Definite CSF flow within the anterior third ventricle was present in 4/5 (SPAMM) and 3/5 (cine PC) successful NTVs, 0/2 (SPAMM and cine PC) unsuccessful NTVs and 1/10 (SPAMM and cine PC) patients without NTV. CONCLUSION: SPAMM provides a comparable assessment of intracranial CSF flow to that of cine phase contrast imaging at all CSF sites except the cerebral aqueduct.     

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.     

Cardiac-gated phase MR imaging of aqueductal CSF flow

The direction of CSF flow within the cerebral aqueduct was studied by cardiac-gated magnetic resonance (MR) phase images in five healthy volunteers and 10 patients with presumably normal cerebral CSF circulation. Caudal CSF flow was observed during systole and cranial flow during diastole. Using phantom based calibrations of the imager, aqueductal CSF velocities of 3-5 mm/s were calculated. Cardiac-gated phase MR is a potentially major tool for the investigation of the CSF circulation.     

Fast multiphase MR imaging of aqueductal CSF flow: 2. Study in patients with hydrocephalus

The signal intensity in the region corresponding to the cerebral aqueduct was evaluated in three patients with noncommunicating tension hydrocephalus (caused by aqueductal obstruction in two and type I Arnold-Chiari malformation in the other), seven patients with suspected normal-pressure hydrocephalus (three of whom subsequently underwent successful shunting), and 10 patients with ex vacuo (atrophic) hydrocephalus. A gradient-echo MR sequence, called fast multiphase imaging, was used. Serial images corresponding to different phases of the cardiac cycle were acquired. No flow-related enhancement was observed over the entire cardiac cycle in the patients with noncommunicating hydrocephalus. Patients with normal-pressure hydrocephalus showed a higher aqueductal CSF signal intensity, consistent with increased systolic flow rates, than patients with ex vacuo hydrocephalus. When comparing the above two groups of patients with a control group of healthy volunteers, significantly higher and lower values of the (mean) maximum aqueductal signal intensity were found in the normal-pressure hydrocephalus patients and the ex vacuo hydrocephalus patients, respectively. Fast multiphase MR evaluation of aqueductal CSF flow may help to differentiate patients with different types of hydrocephalus.     

Flowing cerebrospinal fluid in normal and hydrocephalic states: appearance on MR images

The signal intensity of the cerebrospinal fluid (CSF) in the cerebral aqueduct and lateral ventricles on magnetic resonance (MR) images was evaluated in 16 healthy individuals and in 32 patients with various forms of hydrocephalus (20 with chronic normal pressure hydrocephalus [NPH], seven with acute communicating hydrocephalus, and five with hydrocephalus ex vacuo [atrophy]). The low signal intensity frequently observed in the cerebral aqueduct is believed to reflect the pulsatile motion of CSF, which is related to the cardiac cycle. While this "aqueductal flow void phenomenon" can be observed in healthy individuals, it is most pronounced in patients with chronic, communicating NPH; is less evident in patients with acute, communicating hydrocephalus; and is least evident in patients with atrophy. Ventricular compliance is known to be essentially normal in atrophy; mildly decreased in acute, communicating hydrocephalus; and severely decreased in NPH. The degree of aqueductal signal loss is believed to reflect the velocity of the pulsatile CSF motion, which in turn depends on the relative ventricular compliance and surface area.     

Intracranial CSF flow in pediatric hydrocephalus: evaluation with cine-MR imaging.

PURPOSE: 1) To describe the pattern of normal intracranial CSF flow in children and 2) to demonstrate altered CSF flow patterns in pediatric hydrocephalus and ventriculomegaly with flow-sensitized cine-MR examinations. METHOD: Cardiac gated, multiframe, gradient echo sequences on a 1.5-T system were displayed on a closed loop cine format and compared to standard MR images. Areas of normal flow and areas of diminished flow were determined. RESULTS: 1) In normal children, the CSF flow follows a consistent pattern with a to-and-fro movement of flow in the aqueduct, foramen of Magendie, and in the dorsal and ventral subarachnoid space at the cervicomedullary junction. 2) In patients with ventricular enlargement, the flow studies showed regional abnormalities of the CSF flow patterns: specifically, lack of flow and hyperdynamic flow. CONCLUSION: Cine-MR for CSF flow evaluation is a useful adjunct to routine MR in the evaluation of pediatric hydrocephalus because it can assist in determining the probable level of CSF obstruction.     

Frequency analyses of CSF flow on cine MRI in normal pressure hydrocephalus

Our objective was to clarify intracranial cerebrospinal fluid (CSF) flow dynamics in normal-pressure hydrocephalus (NPH). Frequency analyses of CSF flow measured with phase-contrast cine MRI were performed. The CSF flow spectra in the aqueduct were determined in patients (n=51) with NPH, brain atrophy or asymptomatic ventricular dilation (VD), and in healthy volunteers (control group; n=25). The changes in CSF flow spectra were also analyzed after intravenous injection of acetazolamide. Moreover, a phase transfer function (PTF) calculated from the spectra of the driving vascular pulsation and CSF flow in the aqueduct were assessed. These values were compared with the pressure volume response (PVR). The amplitude in the NPH group was significantly larger than that in the VD or control group because of a decrease in compliance. The phase in the NPH group was significantly different from that in either the VD or the control group, but no difference was found between the VD and control groups. The amplitude increased in all groups after acetazolamide injection. The PTF in the NPH group was significantly larger than in the control group, and a positive correlation was noted between PTF and PVR. Frequency analyses of CSF flow measured by cine MRI make it possible to noninvasively obtain a more detailed picture of the pathophysiology of NPH. Electronic Publication