颅内疾病对导水管脑脊液流量的影响

目的：探讨用磁共振相位对比电影(PC cine)对导水管脑脊液定量测量的临床应用价值。方法：将35例中枢神经系统不同疾病分三组，用PC cine方法进行导水管脑脊液流量测量。结果：在脑血管病组伴白质改变时导水管流量增加；梗阻性脑积水导水管流量减少，流动波形异常；交通性脑积水导水管流量增加，波形圆钝。结论：磁共振PC cine方法测量导水管脑脊液流量简单易行，可为临床提供更多的影像信息。     

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.     

Evaluation of CSF flow patterns of posterior fossa cystic malformations using CSF flow MR imaging

Introduction Differential radiologic diagnosis of cystic malformations of the posterior fossa is often difficult with conventional imaging techniques because of overlapping features of these entities. Posterior fossa cystic malformations occupy the cerebrospinal fluid (CSF) spaces. They may create secondary dynamic effects on the movements of CSF. The aim of this study was to investigate CSF flow alterations in posterior fossa cystic malformations with CSF flow MR imaging.Methods The study included 40 patients with cystic malformations of the posterior fossa. The patients underwent cardiac-gated phase-contrast cine MR imaging. CSF flow was qualitatively evaluated using an in-plane phase-contrast sequence in the midsagittal plane. The MR images were displayed in a closed-loop cine format.Results Twelve of the patients had communicating arachnoid cyst, seven had non-communicating arachnoid cyst, ten had mega cisterna magna, six had Dandy-Walker malformation, two had Dandy-Walker variant, and three had Blake’s pouch cyst. CSF flow MR imaging indicated the regions of no, slow or higher flow, direction of flow, and abnormal cystic fluid motion. Each malformation displayed a distinct CSF flow pattern.Conclusion Phase-contrast cine MR imaging for CSF flow evaluation may be a useful adjunct to routine MR imaging in the evaluation of the cystic malformations of the posterior fossa because it can improve the specificity in differentiating such malformations.Electronic Supplementary Material Supplementary material is available in the online version of this article at Part of this article was presented as a poster exhibition at the ESNR 28th Annual Congress and 12th Advanced Course, 11–14 September 2003, Istanbul.     

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.     

Functional analysis of third ventriculostomy patency by quantification of CSF stroke volume by using cine phase-contrast MR imaging

OBJECTIVE: Endoscopic third ventriculostomy (ETV) is increasingly used as alternative treatment for obstructive hydrocephalus. The aim of this study was to determine the utility of quantitative and qualitative examinations with cine phase-contrast MR imaging to determine the efficacy of ventriculostomy across time and whether CSF pulsation is restored after ETV. METHODS: Thirty-eight patients treated with ETV were evaluated with cine phase-contrast MR within 1 month after surgery. Follow-up studies were performed after 1 year in 25 patients and after 2 years in 12. We evaluated flow void changes in the floor of the third ventricle and quantified the stroke volume at the site of the ventriculostomy. We also recorded changes in ventricular size and clinical outcome. To determine the restoration of CSF pulsation, we compared the CSF waveform at the ventriculostomy with the CSF waveform at the aqueduct in a healthy control group. RESULTS: After ventriculostomy, restoration of pulsate motion characteristics of CSF circulation was observed. The stroke volume registered at ventriculostomy was maintained with time. There was a statistically significant relationship between clinical outcome and stroke volume. Overall flow magnitude was the most effective variable to determine which patients would improve after surgery. Values >75 mm3 showed a sensitivity of 76.7% and a specificity of 87.5% There was no relationship between ventricular size changes and clinical outcome. Patients with primary aqueduct stenosis had the best response to surgery, whereas patients with Arnold Chiari malformation or communicating hydrocephalus had the worst response. CONCLUSION: Quantitative analysis with phase-contrast MR imaging indicates that ETV is an efficient technique for restoring CSF pulsation, with efficacy being maintained during the follow-up controls. Quantification of stroke volume at ventriculostomy is a good indicator of the functional status of ETV, and a high stroke volume in the ventriculostomy appears to be a positive predictor of favorable clinical outcome.     

CSF flow imaging in the management of third ventriculostomy with a reversed fast imaging with steady-state precession sequence

The aim of this study was evaluation of a fast and slow-flow sensitive 2D steady-state free-precession sequence for its capability to prove the patency of endoscopic third ventriculostomy (TVS) in obstructive hydrocephalus, and to exclude communicating third ventricle prior to TVS. We compared gated and ungated variants of this sequence for this purpose. Twenty-three patients with obstructive hydrocephalus underwent 36 MR examinations with a 2D reversed fast imaging with steady-state precession (PSIF) sequence in a retrospectively cardiac gated (cine) and a faster but ungated version beside T1- and T2-weighted sequences in three planes. Thirteen patients were examined both before and after TVS, 4 patients solely before, and 6 patients solely after TVS. Imaging diagnoses were compared with intraoperative findings and clinical findings after TVS. Preoperative diagnosis of non-communicating third ventricle and cisterns was intraoperatively confirmed in 16 of 17 cases. Preoperative MRI was inconclusive in 1 case. Postoperative MRI revealed sufficient TVS in 16 of 19 cases and obstructed TVS in 3 of 19 cases due to several reasons. Findings at MRI were consistent in 19 of 19 cases with the clinical course and intraoperative results. The faster but ungated PSIF sequence was found to be diagnostically equivalent to the cardiac gated cine sequence. The CSF flow imaging with a 2D reversed fast imaging with steady-state precession sequence in conjunction with conventional T1- and T2-weighted images is a fast and reliable tool for pre- and postoperative functional evaluation in third ventriculostomy. Electronic Publication     

Third ventriculostomy patency: comparison of findings at cine phase-contrast MR imaging and at direct exploration.

BACKGROUND AND PURPOSE: Two-dimensional phase-contrast (PC) MR imaging is a known method for evaluating CSF flow after third ventriculostomy. In this study, we attempted to confirm the accuracy of cine PC MR imaging for determining the patency of a third ventriculostomy as compared with direct reexploration of the floor of the third ventricle. METHODS: We examined 11 patients with third ventriculostomies who had a total of 13 reoperations for symptomatic obstructive hydrocephalus. In 12 of the 13 reexplorations, cine PC MR studies were obtained before repeat surgery, and the diagnoses suggested by imaging were compared with intraoperative findings. RESULTS: Four of five patients who had no flow on MR images had new membranes that covered the orifice; the fifth patient still had a small perforation visible at the time of operation. Three of four patients who had subtle flow on MR images were found to have occlusion with new membranes; the fourth had an incomplete new membrane. Finally, two of three who had a patent ventriculostomy had completely open perforations without membrane formation; the third patient had nonobstructive early membrane formation. At 3 months' follow-up, two flow studies were read as subtle without any clinical symptoms; however, these eventually progressed to become symptomatic, and occlusion with new membrane formation was confirmed during surgical reexploration. CONCLUSION: Cine PC MR imaging is a reliable technique for detecting the patency of a third ventriculostomy, but minor flow, as defined in this report, appears to be an early sign of closure.     

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.     

How to perform and interpret cine MR enterography

Magnetic resonance (MR) enterography has become a fundamental tool for small bowel evaluation. Multiphasic cine imaging is a useful component of MR enterography evaluation because it provides functional information about bowel motility. Cine MR enterography can be used to evaluate for strictures and adhesions. Bowel motility evaluation has been shown to increase pathologic lesion detection in Crohn's disease and has been incorporated into disease activity scoring systems. Currently, cine MR enterography remains underutilized. The purpose of this article is to outline how to perform and interpret cine MR enterography. The authors describe how to perform a multiphasic balanced steady state free precession sequence using different MR systems and give practical advice on how to display and interpret the cine sequence. Sample cases illustrate how the cine sequence complements standard MR enterography evaluation with T₂‐weighted, contrast‐enhanced T₁‐weighted, and diffusion‐weighted imaging. J. Magn. Reson. Imaging 2015;42:1180–1189.     

Comparison of cerebral artery blood flow measurements with gated cine and ungated phase-contrast techniques

Cine phase-contrast (PC) magnetic resonance (MR) pulse sequences have been used to measure blood flow in a variety of vessels. Because the cine PC sequence is time-consuming, this prospective study was undertaken to compare it with an ungated PC technique for measuring average blood flow in individual cerebral arteries to potentially achieve substantial time savings. The following cerebral arteries were studied in 10 healthy volunteers: carotid, basilar, middle cerebral, anterior cerebral, and posterior cerebral. Imaging planes were placed perpendicular to the vessel of interest, and velocity encoding, ranging from 40 to 250 cm/sec, was matched to individual arteries. Good correlation between cine and ungated PC blood flow measurements was obtained for both high- and low-flow vessels, with an overall correlation coefficient of 978. The ungated PC sequence, because of its short imaging time, allows measurement of the blood volume flow rate in the circle of Willis in approximately 20 minutes, a clinically acceptable time.     

Peak blood flow measurement of coronary sinus by cine phase contrast MR imagings: comparison between breath-hold and respiratory compensation techniques.

The aim of this study was to assess the feasibility of cine phase contrast (PC) magnetic resonance (MR) imaging for the peak blood flow measurement of the coronary sinus. Conventional PC imaging demonstrated the coronary sinus clearly and the significantly higher peak flow compared with the corresponding values measured with breath-hold fast cine PC imaging techniques at end-inspiration and end-expiration. This study showed the feasibility of conventional cine PC imaging with respiratory compensation in measurement of coronary sinus blood flow.     

Experiences with intrathecally enhanced computed tomography

Summary Computed tomographic cisternography (CTC) shows small normal and pathological structures in the extracerebral CSF spaces in an excellent way and is able to differentiate communicating from non-communicating CSF-containing cysts in congenital malformations and acquired lesions. The main value of the CTC is in the examination of CSF dynamics. A report is given about our experiences with 121 patients. The dynamic flow patterns are divided into eight groups. The results are discussed in detail with suggestions as to the treatment.     

Abdominal phase-contrast MR angiography: Breath-Hold versus non-breath-hold techniques

Breath-hold magnetic resonance (MR) imaging is now replacing many non-breath-hold pulse sequences in the upper abdomen because of faster imaging times and improved image quality. The authors compared non-breath-hold cine phase-contrast (PC) and breath hold 2D phase-contrast (2DPC) magnetic resonance (MR) angiograms of the main portal vein (MPV) and superior mesenteric artery (SMA) in 12 volunteers. All angiograms were graded in overall image quality, vessel conspicuity, and signal-to-noise ratios (SNR). In the MPV MR angiograms, the breath-hold 2DPC sequence produced better images than the non-breath-hold cine PC sequence as graded by overall image quality (P=.016) and SNR (P=.004). Conversely, in the SMA MR angiograms, the non-breath-hold cine PC sequence produced better images than the breath-hold sequence in terms of overall image quality (P=.008) and SNR (P=.008). By reducing the most significant cause of image artifacts, (ie, using a breath-hold 2DPC sequence to decrease respiratory misregistration of the MPV, and using a cardiac-gated cine PC sequence to minimize pulsatile artifacts of the SMA), one can clearly optimize the quality of MR angiography.     

HASTE sequence and cine-MRI evaluation of the cervical spinal canal: evaluation in 11 healthy subjects

PURPOSE: We studied 11 healthy subjects were evaluated using cine MR imaging comparing HASTE and gradient echo sequences. Materials and methods :HASTE is a high-speed turbo-spin echo T2-weighted sequence. All examinations were performed using dynamic MRI using a simple process allowing acquisition of images at different stages during flexion and extension. The cine MR evaluation was obtained by rebuilding a cine-loop sequence. RESULTS: HASTE sequence provides a myelographic effect of the cervical spine. The size, the pattern and the movements of the cervical spine, the spinal cord, as well as the functional reserve of cerebro-spinal fluid are analysable. CONCLUSION: Because of its very high speed, HASTE sequence is particularly useful for cine MR imaging.     

Phase-contrast cine MRI versus MR cisternography on the evaluation of the communication between intraventricular arachnoid cysts and neighbouring cerebrospinal fluid spaces

Introduction  The objective of this study was to evaluate the role of phase-contrast cine magnetic resonance imaging (PC-MRI) in detecting possible communications between intraventricular arachnoid cysts (IV-ACs) and cerebrospinal fluid (CSF) spaces based on MR cisternography (MRC) comparison. Materials and methods  Twenty-one patients with IV-AC were examined by PC-MRI and MRC. In order to determine the communication of IVAC with its neighbouring CSF spaces, PC-MRI was employed. The communication of IV-ACs with the ventricular system was examined on at least two anatomic planes. Precontrast images and PC-MRI were followed by the intrathecal administration of 0.5–1 ml gadopentetate dimeglumine. Early and delayed MRC were then carried out. Results of PC-MRI were compared with findings of MRC (McNemar’s test). Results  In seven IV-ACs, no communication was detected by PC-MRI. In 14 IVACs, a pulsatile CSF flow into the IV-ACs was observed. All the IV-ACs, which have been determined as non-communicating (NC) on the PC-MRI, showed NC character on MRC as well. Six cases suggesting a communication on PC-MRI showed no communication on MRC. MRC revealed eight communicating (38%) and 13 NC (62%) IV-ACs among a total of 21 cases. The sensitivity and specificity of PC-MRI imaging in demonstrating the communication between the IV-ACs and the CSF were 100% and 54%, respectively. Conclusion  PC-MRI is an effective method for evaluating NC IV-ACs. In order to decide about the management of IV-ACs, which are communicating according to the PC-MRI, the results should be confirmed with MRC if suspected jet flow is depicted.     

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.     

MRI电影相位对比法液体流速与信号强度的实验研究

目的：评估磁共振电影相位对比法对液体流速的实验价值。材料和方法：在１．５Ｔ磁共振机上利用磁共振电影相位对比法,在高压注射器分别匀速注射为０．１ｍｌ／ｓ、０．２ｍｌ／ｓ及０．３ｍｌ／ｓ时,对三根截面积分别为４ｍｍ２、５ｍｍ２及１３ｍｍ２的管道内液体流动情况进行测定,在工作站上根据不同流动速度测得相应的信号强度值。结果：三组数值经计算机处理后Ｒ２＝０．９９８,显示相关性极佳;信号强度值（ｙ）与流速（ｘ）之间公式为：ｙ＝－０．０１４１ｘ＋５１．７３５ｘ＋２７．４７８。结论：在实验测定液体流速与信号强度数值时,ＭＲ电影相位对比法是一种有效的方法。     

Magnetic resonance 4D flow characteristics of cerebrospinal fluid at the craniocervical junction and the cervical spinal canal

Objectives

To evaluate the applicability of 4D phase contrast (4D PC) MR imaging in the assessment of cerebrospinal fluid dynamics in healthy volunteers and patients with lesions at the craniocervical junction or the cervical spinal canal.

Methods

Ten healthy volunteers and four patients with lesions including Chiari I malformation and cervical canal stenoses were examined by a cardiac-gated 4D PC imaging sequence on 1.5T MRI. Phase contrast images were postprocessed allowing for flow quantification and flow pathline visualisation. Velocity data were compared with conventional axial 2D phase contrast images.

Results

The 4D PC sequence allowed for flow quantification and visualisation in all individuals. Bland-Altman analysis showed good agreement of 2D and 4D PC velocity data. In healthy volunteers, CSF flow was homogeneously distributed in the anterior and anterolateral subarachnoid space with the flow directed caudally during systole and cranially during diastole. Flow velocities were closely related to the width of the subarachnoid space. Patients showed grossly altered CSF flow patterns with formation of flow jets with increased flow velocities.

Conclusions

4D PC MR imaging allows for a detailed assessment of CSF flow dynamics helping to distinguish physiological from complex pathological flow patterns at the craniocervical junction and the cervical spine.     

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