A Dissipation Function-Based Method for Calculating the Energy Loss of Intracranial Aneurysms

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Medical Physics

Background:

• Current understanding of intracranial aneurysm (IA) rupture mechanisms relies on global energy loss (EL) calculations.
• The detailed temporal and spatial characteristics of EL in IAs remain unclear, limiting a full understanding of rupture.
• Traditional methods, like the Bernoulli equation, provide limited insight into localized EL dynamics.

Purpose of the Study:

• To explore the temporal and spatial characteristics of energy loss (EL) in intracranial aneurysms (IAs).
• To propose and validate a novel method for calculating EL in IAs based on the dissipation function (DF).
• To elucidate the underlying mechanisms of EL in IAs for improved rupture risk assessment.

Main Methods:

• A novel method using the dissipation function (DF) was developed to calculate localized EL.
• Three-dimensional (3D) geometric models of eight sidewall IAs were created from patient data.
• Computational fluid dynamics (CFD) simulations were performed to analyze hemodynamic parameters and EL characteristics.

Main Results:

• Energy loss (EL) predominantly occurs in the boundary layer and near high-velocity inflow jets within IAs.
• EL escalates rapidly during cardiac systole, peaking at the end-systolic phase.
• EL gradually diminishes throughout diastole, offering a detailed temporal profile.

Conclusions:

• The proposed DF-based method provides a more detailed analysis of EL in IAs compared to traditional methods.
• Understanding the temporal and spatial distribution of EL offers critical insights into IA rupture mechanisms.
• This approach can significantly contribute to further investigations into IA rupture and potentially inform clinical risk assessment.