Cerebrospinal fluid flow dynamics in the aqueduct of Sylvius for rigid and deformable brain models.

The cerebrospinal fluid (CSF) in the subarachnoid space and brain ventricles is crucial for maintaining brain health and influencing conditions such as hydrocephalus. This study explores CSF flow dynamics in the aqueduct of Sylvius (AoS) using rigid and deformable brain models based on MRI-derived 3D geometries. The rigid model captures the main characteristics of the CSF velocity waveform in the AoS, particularly in terms of waveform and timing of peaks and troughs. This model also predicts velocity increases in hydrocephalic conditions and velocity ranges in subarachnoid space. However, the rigid model falls short of representing the full range of velocity variations in the AoS. Using fluid-structure interaction simulation, the deformable model addresses the impact of brain tissue deformation on CSF flow. The deformable brain model have an excellent prediction and agrees with MRI measurements, effectively anticipating CSF flow dynamics and flow reversals, underscoring the importance of incorporating brain tissue deformation for accurate modeling. We also found out that the effect of the inlet waveform is critical on the model prediction for the velocity within AoS during a cardiac cycle.