الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The aim of our study was to determine the value of cine phase contrast MRI in characterizing CSF flow in patients presenting with aqueductal stenosis, in NPH patients and in particular to differentiate NPH from cerebral atrophy. Also we wanted to establish how this technique could be helpful in determining the clinical significance of findings associated with Chiari I malformation.
Our study population included 20 patients, 8 presenting with NPH, 6 with suspected cerebral atrophy versus NPH, 5 with aqueductal stenosis, and a Chiari I malformation patient. Two protocols of examination were used, one assessing CSF flow dynamics at the level of the aqueduct of Sylvius both quantitatively using an axial imaging plane perpendicular to the aqueduct, and qualitatively with a sagittal in plane assessment. The other protocol was used for the patient presenting with the Chiari I malformation and involved an assessment of CSF flow dynamics in the axial plane throughout the foramen magnum. The control population included 10 healthy volunteers, all of them were examined according to the first protocol and were used as controls for cases of NPH, cerebral atrophy and aqueductal stenosis & 4 of them examined according to the second protocol and used as control for Chiari I patients.
The production and flow of human cerebrospinal fluid has been studied since the 1940s, however, early investigations were hampered by a lack of non-invasive studies. Magnetic resonance investigation in CSF flow began with the qualitative observation of the degree of flow void in the aqueduct of Sylvius and adjacent third and fourth ventricles. Although this early MR method was useful in the evaluation of patients with suspected NPH, the clinical success was limited and this observational method was not significantly used because the presence of flow void phenomenon in the aqueduct is a qualitative measure, which is influenced by many acquisition parameters, and often may be difficult to quantify. Phase contrast cine MR flow imaging provides a simple way to better characterize CSF flow.
The application of cine phase-contrast MRI technique in normal pressure hydrocephalic patients holds great promise for improved diagnosis, particularly in those cases where the differentiation from atrophy on clinical and conventional radiological basis is difficult. In the normal patient, consistent flow patterns are observed and are quite different from those patterns that are seen in CSF flow disorders. The information obtained with cine phase-contrast MRI often is not readily apparent on routinely acquired MR images and may help to answer the question of whether the ventriculomegaly observed on routine MR is associated with patent or obstructed CSF pathways and to determine the exact level of obstruction. When patients are evaluated clinically for possible CSF diversionary procedure or foramen magnum decompression, a cine phase contrast MR may provide valuable evidence that such surgery is indicated or not as it provides a mapping of CSF velocity and measures the CSF stroke volume in any region of interest along the CSF pathway.