Is Accurate Lumen Segmentation More Important than Outlet Boundary Condition in Image-Based Blood Flow Simulations...

Area of Science:

• Computational fluid dynamics
• Medical imaging
• Biomechanical engineering

Background:

• Image-based blood flow simulations are crucial for understanding intracranial aneurysm (IA) hemodynamics.
• Variability in segmentation and boundary conditions (BCs) impacts simulation reliability.
• This study quantifies these influences on hemodynamic parameters.

Purpose of the Study:

• To analyze the impact of segmentation variability and different boundary conditions (BCs) on hemodynamic parameters in intracranial aneurysms (IAs).
• To compare various outlet BCs, including zero-pressure, Murray's law, and advanced flow-splitting models.
• To assess the influence of segmentation fidelity on hemodynamic predictions.

Main Methods:

• Investigated five intracranial aneurysms (IAs) with varying sizes and locations.
• Applied five distinct outlet boundary conditions (BCs) to each IA model.
• Conducted 120 time-dependent blood flow simulations, analyzing intra-aneurysmal flow and shear parameters.

Main Results:

• Advanced flow-splitting BCs yielded higher shear stresses, velocities, and vorticities compared to zero-pressure BCs.
• Segmentation variability introduced significant deviations in hemodynamic parameters (up to Δ19.58 Pa, Δ0.42 m/s, Δ957.27 1/s).
• Excluding low-fidelity segmentations reduced deviations by over 43% and lessened BC impact.

Conclusions:

• Realistic lumen segmentation, achievable with high-resolution imaging, decreases the influence of BCs on hemodynamics.
• Advanced outflow-splitting models are recommended for IA simulations.
• Zero-pressure BCs and Murray's law BCs (n=3) should be avoided for accurate hemodynamic analysis.