RT Journal Article SR Electronic T1 Peak Systolic and Diastolic CSF Velocity in the Foramen Magnum in Adult Patients with Chiari I Malformations and in Normal Control Participants JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 169 OP 176 VO 24 IS 2 A1 Victor M. Haughton A1 Frank R. Korosec A1 Joshua E. Medow A1 Maria T. Dolar A1 Bermans J. Iskandar YR 2003 UL http://www.ajnr.org/content/24/2/169.abstract AB BACKGROUND AND PURPOSE: Abnormal flow of CSF through the foramen magnum has been implicated in the pathogenesis of clinical deficits in association with Chiari I malformation. The purpose of this study was to test the hypothesis that peak CSF velocities in the foramen magnum are increased in patients with Chiari I malformations.METHODS: Eight adult patients with symptomatic Chiari I malformations and 10 adult volunteers were studied with cardiac gated, phase-contrast MR imaging in the axial plane at the foramen magnum. The spatial uniformity of flow velocity in the foramen magnum was assessed at 14 time frames within the R–R interval. The velocity in each of the voxels at each of the time frames was calculated, and the peak systolic and diastolic velocities were tabulated for the patients and controls.RESULTS: For the normal volunteers, the CSF velocities in the subarachnoid space were relatively uniform throughout the subarachnoid space at each of the time frames. Peak systolic velocity ranged from 1.2 to 3.3 cm/s, and peak diastolic velocity ranged from 1.6 to 4.5 cm/s. In symptomatic patients with Chiari I, velocities in the foramen magnum did not appear as uniform throughout the subarachnoid space in the phase-contrast images. Peak systolic velocities ranged from 1.8 to 4.8 cm/s, and peak diastolic velocities ranged from 2.5 to 5.3 cm/s. Peak systolic velocity was significantly higher (P = .01) in the patients than in the control volunteers.CONCLUSION: Patients with Chiari I malformations have significant elevations of peak systolic velocity in the CSF in the foramen magnum.