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.     

Cerebrospinal fluid flow in patients with dilated ventricles studied with MR imaging

The purpose of this study was to measure the cerebrospinal fluid (CSF) velocity and flow in the aqueduct in patients with wide ventricles with or without signs of normal pressure hydrocephalus (NPH) before and after shunt surgery. We studied 18 patients with wide ventricles with MRI and measured the CSF velocity values in the aqueducts. Twelve patients with the clinical triad of NPH were examined. Six patients were studied only before shunt surgery and 6 patients were studied both before and after shunt surgery. Three patients with wide ventricles without clinical triad of NPH, and 3 patients with hydrocephalus following subarachnoid hemorrhage were also examined. Seven NPH patients with hyperdynamic CSF flow and three NPH patients with normal CSF velocity and flow values showed a positive clinical response to shunt surgery. Two of the three patients with hydrocephalus and hyperdynamic CSF flow values in the aqueduct secondary to subarachnoid bleeding responded to shunt surgery. One patient with same disease and low CSF velocity and flow values did not respond. No change was detected in the CSF flow values of the aqueduct when measurements before and after shunt surgery were compared. Ventriculoperitoneal shunting does not change the CSF dynamics in the aqueduct. Received: 8 March 1999; Revised: 30 November 1999; Accepted: 23 February 2000     

MR imaging of the neural foramina of the cervical spine. Comparison of 3D-DESS and 3D-FISP sequences

Purpose: To assess whether a single three-dimensional double-echo steady state (3D-DESS) sequence can produce equivalent results when compared to a 3D free induction with steady precession (3D-FISP) sequence for the evaluation of the neural foraminal diameter and structures.Material and Methods: Five phantoms were imaged on CT with 3-mm axial slices followed by reformatted axial 3D-DESS and 3D-FISP sequences. In addition, 3D-DESS and 3D-FISP sequences of 20 healthy subjects were compared with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural foramina, and differentiation between vertebrae and neural foramina.Results: Compared with CT, 3D-DESS and 3D-FISP sequences consistently underestimated the diameters of the neural foramina. The mean difference values for the 3D-DESS was 12.8%, compared to 9.5% for the 3D-FISP sequence. Concerning the in vivo studies, the 3D-DESS sequence was superior but not statistical significant to the 3D-FISP sequence with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural formina, and identification of the nerve roots.Conclusion: The 3D-DESS sequence is moderately accurate in the evaluation of the neural foraminal size. Compared to the 3D-FISP sequence, the 3D-DESS sequence is compatible concerning the image quality, differentiation between the cervical vertebrae and discs, and between the discs and neural foramina.     

Cerebrospinal fluid flow and production in patients with normal pressure hydrocephalus studied by MRI

An interleaved velocity-sensitised fast low-angle shot pulse sequence was used to study cerebrospinal fluid (CSF) flow in the cerebral aqueduct, and supratentorial CSF production in 9 patients with normal pressure hydrocephalus (NPH) and 9 healthy volunteers. The peak aqueduct CSF flow, both caudal and rostral, was significantly increased in patients with NPH. No significant difference in the supratentorial CSF production rate was found between patients (mean 0.60+/–0.59 ml/min) and healthy volunteers (mean 0.68+/–0.31 ml/min). Our method may be useful for investigation and monitoring of patients with NPH before and after ventriculoperitoneal shunt operations.     

Development of a mathematical model of the cervical spinal canal and its use in detecting early pathologic changes

Summary Detection of subtle osseous changes on plain film roentgenograms of the cervical spine is essential in expediting the evaluation of suspected intraspinal tumors. It is our experience that the earliest osseous changes in such cases involve thinning or erosion of the adjacent pedicles and/or lamina and a subsequent increase in the oblique diameter of the cervical spinal canal. A statistical model is established which accurately describes the normal cervical vertebral column in terms of its spinal canal size (sagittal and oblique diameters) as well as pedicle and lamina thickness. Data was obtained from a series of 86 normal exams. Six surgically proven cases of cervical intraspinal tumors were analyzed using this model. Variations from expected normal values reveal statistically significant osseous changes involving thinning of the lamina and increased oblique diameter of the spinal canal, while the sagittal diameter of the canal remains normal. Because of these findings we feel that oblique cervical spine films should be included in the initial evaluation of neural canal tumors.     

Percutaneous access to the anterior spinal canal through a cervical disk

We describe a CT-guided percutaneous technique for aspiration of an anterior intraspinal fluid collection through a cervical disk. The approach is identical to that of cervical diskography or percutaneous cervical diskectomy, with intentional placement of the needle tip in the spinal canal. This procedure had no adverse effects and avoided an open operation to exclude spinal cord compression. Received: 13 October 1997 Accepted: 20 January 1998     

Upper cervical spinal cord compression due to bony stenosis of the spinal canal

Compression of the upper cervical spinal cord due to stenosis of the bony spinal canal is infrequent. In the first case reported here, stenosis was due to acquired extensive, unilateral osteophytes centered on the left apophyseal joints of C1–C2 in an elderly professional violinist. In the second case, stenosis was secondary to isolated congenital hypertrophy of the laminae of C1 and C2.     

Quantitative analysis of the cervical spinal canal by computed tomography

Summary Computed tomography measurements of the AP diameter, width, and cross-sectional area of the bony cervical canal were derived from cervical spine examinations of fifty-two normal adults. These quantitative parameters were then used to evaluate 80 patients with various cervical abnormalities to determine the clinical usefulness of the measurements. With the exception of spinal stenosis, quantitative cervical canal analysis was found to be of limited usefulness since normal measurements frequently occurred in the presence of significant cervical pathology.Protions of this material was presented at the Annual Meeting of the Radiological Society of North America Chicago, Illinois, November 14–18, 1983     

Central spinal cord lesions in stenosis of the cervical canal

Summary 34 patients suffering from cervical spondylotic myelopathy confirmed by myelography were examined by delayed CT 6–10 h after myelography. Twelve patients showed bilateral intramedullary collections of contrast medium, predominantly cranial to the stenosis. In these patients males predominated, the duration of clinical symptoms lasted longer although their age was lower. There was no correlation to the degree and the extension of the narrowing of the cervical spinal canal. Half of 20 patients undergoing consecutive decompressive surgery showed intramedullary contrast enhancement, and this was shown again by postoperative MRI in eight. The postoperative clinical and neurophysiological results revealed no change in the majority of patients, but three patients showing intramedullary contrast medium deteriorated in neurophysiological outcome, while only one of the patients in whom intramedullary contrast medium was not noticed got worse.     

Further aspects of MR-signal enhancements in stenosis of the cervical spinal canal

Summary The validity and anatomical basis of increased MR-signal intensity of the cord in cervical canal stenosis is discussed with respect to our own data of 32 patients (including results of clinical, CSF and other imaging technique findings) and previous reports. A shear-stress hypothesis with edematous tissue changes is favoured.     

颈椎病动态MRI扫描揭示椎管狭窄及脊髓受压因素的价值

颈椎动态MRI扫描直观地显示屈伸状态下导致椎管狭窄及脊髓受压的动态因素,为临床提供了中立位扫描所不能揭示的致病机制,以后伸位为著。后伸位颈椎功能性受压与颈椎退变阶段及椎管矢径密切相关,当中立位MRI显示黄韧带肥厚,或椎关节僵硬伴发椎管矢径≤10.0mm时,建议行动态MRI扫描。前屈位虽然可以减轻脊髓受压,但持久前屈会促使或加重颈椎病的发生。     

Congenital spondylolysis of cervical vertebrae with spondylolisthesis and frontal narrowing of the spinal canal

Summary Two cases of cervical spondylolisthesis, due to a congenital defect in the pars interarticularis of C₆, associated with spina bifida and elongation of the contralateral pars interarticularis, are reported. Tomography showed an abnormal direction of the articular facets of C₆ and demonstrated a narrow frontal diameter of the cervical spinal canal at the level of the malformation. Gas myelography showed a slight compression of the cord. Unlike previously reported cases the patients had neurological findings which, in one case at least, were certainly referable to the spinal cord.     

正常脑脊液循环的MRI定量研究

目的运用MRIcine相位对比法研究正常志愿者的脑脊液流动.材料和方法采用MRIcinePC对40例正常志愿者颅内及椎管脑脊液循环进行研究,男29例,女¨例,年龄7～76岁.对其中31例作了中脑导水管、枕大孔和C2水平的脑脊液流动方向、流速和流量的研究,9例测定了T6及L1水平的脑脊液流动方向.结果(1)心房收缩期和心室收缩期,脑脊液自第三脑室向下流人第四脑室;心室舒张期,则脑脊液流动方向相反.椎管内心脏收缩期和舒张期脑脊液流动方向与中脑导水管基本相同,即收缩期脑脊液向下流动,而舒张期脑脊液向上流动.脑脊液在椎管内的流动方向蜿蜒曲折,颈和腰段椎管内能测得明显脑脊液流动和确定其流向的部位在椎管的前部,而胸段则在椎管的后部.(2)每个心动周期中脑导水管脑脊液向下峰速和向上峰速分别为15.6±6.58mm/s和15.92±6.79mm/s,中脑导水管的向下流量及向上流量分别为0.547±0.208ml/s及0.538±0.208ml/s,净向下流量为0.009±0.008ml/s;枕大孔脑脊液向下峰速和向上峰速分别为2.47±0.98mm/s和2.94±1.34mm/s,向下流量及向上流量分别为0.534±0.249ml/s及0.530±0.250ml/s,净流量为0.004±0.002ml/s;C2层面脑脊液向下峰速和向上峰速分别为4.72±1.86mm/s和4.89±1.78mm/s,向下流量及向上流量为1.106±0.476ml/s和1.101±0.476ml/s,净流量0.005±0.003ml/s.结论MRIcinePC能无损伤地研究人体脑脊液的流动和比较精确地确定脑脊液的流速、流量和方向,是一种优于其他方法的研究CSF流动的重要方法,在此基础上能进一步对脑脊液循环障碍疾病进行定量研究.     

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.     

颅颈交界区及颈椎管脑脊液的MR 4D流动特征

目的评估MR4D相位对比(4D PC)成像对健康志愿者和颅颈交界区或颈椎管病变病人的脑脊液动力学的实用性。方法 10名健康志愿者以及4例病人(包括ChiariⅠ型畸形和颈椎椎管狭窄)行1.5 T MR心脏门控下4D PC成像。     

Upper thoracic-spine disc degeneration in patients with cervical pain

Objective To study the relationship of upper thoracic spine degenerative disc contour changes on MR imaging in patients with neck pain. The relation between upper thoracic and cervical spine degenerative disc disease is not well established.Design and patients One hundred and fifty-six patients referred with cervical pain were studied. There were 73 women and 77 men with a mean age of 48.6±14.6 years (range, 19 to 83 years). All MR studies were performed with a large 23-cm FOV covering at least from the body of T4 to the clivus. Discs were coded as normal, protrusion/bulge or extrusion.Results Degenerative thoracic disc contour changes were observed in 13.4% of patients with cervical pain. T2–3 was the most commonly affected level of the upper thoracic spine, with 15 bulge/protrusions and one extrusion. Upper degenerative thoracic disc contour changes presented in older patients than the cervical levels (Student-Newman-Keuls test, P<0.001). Degenerative disc contour changes at the C7–T1, T1–2, T2–3 and T3–4 levels were significantly correlated (P=0.001), but unrelated to any other disc disease, patients gender or age. Degenerative cervical disc disease was closely related together (P<0.001), but not with any thoracic disc.Conclusion A statistically significant relation was found within the upper thoracic discs, reflecting common pathoanatomical changes. The absence of relation to cervical segments is probably due to differences in their pathomechanisms.This paper was presented at the 9th Scientific Meeting and Exhibition of the International Society for Magnetic Resonance in Medicine and the 18th Annual Meeting and Exhibition of the European Society for Magnetic Resonance in Medicine and Biology, which were held jointly in Glasgow, Scotland, UK, April 2001.     

Cerebrospinal fluid PCR analysis and biochemistry in bodies with severe decomposition

The aim of this study was to assess whether Neisseria meningitidis, Listeria monocytogenes, Streptococcus pneumoniae and Haemophilus influenzae can be identified using the polymerase chain reaction technique in the cerebrospinal fluid of severely decomposed bodies with known, noninfectious causes of death or whether postmortem changes can lead to false positive results and thus erroneous diagnostic information. Biochemical investigations, postmortem bacteriology and real-time polymerase chain reaction analysis in cerebrospinal fluid were performed in a series of medico-legal autopsies that included noninfectious causes of death with decomposition, bacterial meningitis without decomposition, bacterial meningitis with decomposition, low respiratory tract infections with decomposition and abdominal infections with decomposition. In noninfectious causes of death with decomposition, postmortem investigations failed to reveal results consistent with generalized inflammation or bacterial infections at the time of death. Real-time polymerase chain reaction analysis in cerebrospinal fluid did not identify the studied bacteria in any of these cases. The results of this study highlight the usefulness of molecular approaches in bacteriology as well as the use of alternative biological samples in postmortem biochemistry in order to obtain suitable information even in corpses with severe decompositional changes.     

Intradural extramedullary spinal canal secondary neoplasms: MR findings in 30 patients

The purpose of this study was to describe magnetic resonance findings of intradural spinal canal secondaries and to select the best way of investigating this condition. Thirty patients with a known malignancy [breast carcinoma (n = 14), lung carcinoma (n = 10), other sites (n = 6)] and unexplained neurologic signs were studied with pre- and post-contrast T1-weighted images and T2-weighted images. Cerebrospinal fluid cytology was available in 16 patients and positive in 11 patients. In all the patients, post-contrast T1-weighted images demonstrated abnormal enhanced lesions. Most of them were nodular, located on the conus medullaris and the cauda equina. Few lesions appeared at the thoracic or cervical levels, as nodular or thin areas of enhancement. Pre-contrast T1-weighted sequences failed or were equivocal to detect the lesions. Eighteen of 30 patients had cerebral metastases. Fourteen had osseous metastases. In conclusion, post-contrast T1-weighted sequence is the optimal modality for the diagnostic of intradural spinal canal metastases. Axial and coronal images may be a useful adjunct to precise anatomic changes. T1-weighted and T2-weighted sequences remain necessary when further information is expected on vertebra or soft tissue. Received 25 September 1997; Revision received 29 December 1997; Accepted 5 January 1998