A New Model of Intracranial Dynamics

Phase Contrast and Echo Planar MRI Studies of Pulsatile Blood and Cerebrospinal Fluid Flow

Michael Egnor, M.D.

SUNY Stony Brook, Stony Brook, NY

Grant Program:

David Mahoney Neuroimaging Program

Funded in:

January 2003, for 1 years

Funding Amount:

$100,000

Investigator Biographies

Michael Egnor, M.D.

Associate Professor of Neurosurgery, SUNY Stony Brook, NY

Hypothesis

Hypothesis:
The primary hypothesis of this pilot study is that a new model of pulsatile intracranial dynamics can be used to develop a better understanding of CSF flow-related disorders. The model simulates pulsatile intracranial dynamics as a forced oscillator with one or two degrees of freedom.

Goals:
MRI flow imaging techniques will be used to study three specific disease states that have not been fully understood in the past: hydrocephalus, syringomyelia, and herniated discs. We will first establish a set of normal values for pulsatile velocity of blood and CSF in various regions of the cranium and spine. We will then test the hypothesis that abnormalities of these flow patterns are seen in hydrocephalus, syringomyelia, and herniated discs, and that the measured abnormalities are consistent with our model. Finally, we will new treatment strategies for these disorders that are suggested by the model.

Methods:
The imaging protocol will include: 1) ECG-gated MRI images, using phase contrast, to provide gated cine flow velocity information, and 2) High temporal resolution echo-planar images. A control population of 30 normal volunteers will be recruited for a database of normal flow patterns. Then, 15 patients in each of the three groups will be recruited to study alterations in the flow patterns, and new treatments will be simulated on the model.

Selected Publications

McCormack, E.J., Egnor, M.R., and Wagshul, M.E. Improved cerebrospinal fluid flow measurements using phase contrast balanced steady-state free precession. Magn Reson Imaging. 2007 Feb;25(2):172-82 .

Wagshul M.E., Egnor, M.R., Chen J.J., McCormack, E.J., and Roche, P.E. Amplitude and phase of cerebrospinal fluid pulsations. Experimental results and review of the literature. J Neurosurg. 2006 May;104(5):810-9 .