CSF velocity magnitudes simulated by CFD at various axial cross-sections shown at diastolic and systolic peak flow for the Healthy and CP2-pre case.

<p>Inset of flow waveform (red trace) indicates portion of CSF flow cycle that each plot is given (blue vertical line).</p

Distributions of hydrodynamic parameters computed for each case.

<p>Position is relative to the location of the foramen magnum moving caudally down the SAS. Highlighted segment of waveforms indicate values in the first 2.5</p

CFD simulation information for all cases.

<p>CFD simulation information for all cases.</p

Maximum velocities and pressure drops.

<p>Maximum velocities and pressure drops.</p

Pressure drop (dP) in the caudal direction computed over the first 2.5 cm of each CFD model.

<p>Pressure drop (dP) in the caudal direction computed over the first 2.5 cm of each CFD model.</p

CSF flow waveforms at C2 for each case (Q represents flow).

<p>Note, positive flow is in the caudal direction and negative flow is in the cranial direction.</p

Simplistic representation and corresponding MR images (T1) of the CSF system around the brain and cervical spine for a Chiari patient with syringomyelia showing location of the syrinx (blue region in center of spinal cord) and tonsillar herniation (red at base of brain).

<p>Simplistic representation and corresponding MR images (T1) of the CSF system around the brain and cervical spine for a Chiari patient with syringomyelia showing location of the syrinx (blue region in center of spinal cord) and tonsillar herniation (red at base of brain).</p

Integrated longitudinal impedance (LI) for each case.

<p>Integrated longitudinal impedance (LI) for each case.</p

Meshed 3D reconstructions (sagittal view) of the cervical spinal SAS geometries used for the CFD simulations: healthy volunteer and two CMI patients before and after decompression surgery.

<p>Note: flow extensions used for the CFD simulations were not included in this figure.</p