Understanding Angiography-Based Aneurysm Flow Fields through Comparison with Computational Fluid Dynamics

Area of Science:

• Medical Imaging
• Fluid Dynamics
• Neurosurgery

Background:

• Hemodynamics significantly influences aneurysm progression and rupture.
• Accurate flow field representation is crucial for understanding intracranial aneurysms.

Purpose of the Study:

• To assess if dynamic angiography (DSA) can realistically depict intracranial aneurysm flow fields.
• To compare DSA-based flow reconstructions with computational fluid dynamics (CFD) models.

Main Methods:

• DSA-based flow reconstructions were compared to patient-specific CFD models in 15 cerebral aneurysms.
• Qualitative comparison and quantitative vector field similarity analysis were performed.

Main Results:

• Average similarity between DSA and projected CFD flow fields was 78% in parent arteries but only 30% in aneurysm regions.
• Both methods captured inflow jets, vortex structures, and flow splits in approximately 60% of cases.

Conclusions:

• 3D intrasaccular flow, inflow jets, vortex alignment, vessel overlap, and frame rate affect DSA flow reconstruction accuracy.
• Multiple DSA projections are necessary for understanding 3D intrasaccular flow.
• DSA provides a good representation of mean axial flow and flow rate despite limitations with swirling/secondary flows.