Aneurysm Neck Overestimation has a Relatively Modest Impact on Simulated Hemodynamics

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Intracranial aneurysm neck width overestimation in 3D angiography is a known issue impacting computational fluid dynamics (CFD) analysis.
• Segmentation with upsampled resolution and gradient enhancement (SURGE) can correct this overestimation.

Purpose of the Study:

• To evaluate the impact of neck overestimation in 3D rotational angiography (3DRA) on CFD-derived hemodynamics.
• To determine if and how correcting neck overestimation affects hemodynamic parameters.

Main Methods:

• 17 cases with significant neck overestimation were segmented using standard watershed and SURGE methods from 3DRA.
• High-fidelity, pulsatile CFD simulations were performed on both corrected and uncorrected models.
• Hemodynamic parameters associated with aneurysm growth and rupture were derived.

Main Results:

• Flow and wall shear stress (WSS) patterns were largely similar between corrected and uncorrected models.
• Sac-averaged WSS was significantly lower in corrected models but highly correlated (R²=0.98).
• Jet impingement became more concentrated in corrected models, with moderate correlation (R²=0.61).

Conclusions:

• Differences in hemodynamics due to neck width overestimation are comparable to or less than other CFD error sources.
• The impact of neck overestimation on CFD is less significant than previously assumed.
• Neck width correction using SURGE provides more accurate hemodynamic insights for intracranial aneurysms.