Quantitative Comparison of 3D-1D Vascular Coupling Models: Lateral Average versus Sphere of Influence Methods

Area of Science:

• Computational fluid dynamics
• Biomedical engineering
• Mathematical modeling

Background:

• Computational models coupling 1D vascular networks and 3D tissue domains are essential for predicting blood flow in applications like tumor perfusion and drug delivery.
• Two primary coupling paradigms, the Lateral Average Model (LAM) and the Sphere of Influence (SOI) model, are widely used but lack systematic quantitative comparisons.

Purpose of the Study:

• To systematically compare the parametric behavior and predictive equivalence of the LAM and SOI models in 3D-1D simulations.
• To provide guidance on selecting the appropriate coupling model based on specific clinical or research questions.

Main Methods:

• Comparison of LAM and SOI models using 3D-1D simulations on a benchmark vascular network and a porcine liver arterial network reconstructed from CT arteriography.
• Analysis of global flow rates and regional perfusion fractions under varying model parameters (vessel wall conductivity γ for LAM, source sphere radius ε for SOI).

Main Results:

• Global flow equivalence between LAM and SOI is geometry-dependent and not universally achieved.
• Significant divergence in regional perfusion predictions between LAM and SOI, even when total flow is comparable.
• LAM predictions for regional perfusion varied with vessel wall permeability, potentially inverting flow distribution, while SOI showed stable regional perfusion fractions.

Conclusions:

• The choice of coupling model (LAM vs. SOI) has minimal impact on predicted total organ flow but a substantial impact on predicted local drug delivery.
• Guidance is provided for selecting between LAM and SOI based on the specific research or clinical question, emphasizing the importance of regional perfusion accuracy for drug delivery applications.