Computational Fluid Dynamics Modeling of Intracranial Aneurysms:1

Rationale and Objective

The purpose of this study is to determine whether computational fluid dynamics modeling can correctly predict the location of the major intra-aneurysmal flow structures that can be identified by conventional angiography.

Materials and Methods

Patient-specific models of three cerebral aneurysms were constructed from three-dimensional rotational angiography images and computational fluid dynamic simulations performed. Using these velocity fields, contrast transport was simulated and visualizations constructed to provide a “virtual” angiogram. These models were then compared to images from high frame rate conventional angiography to compare flow structures.

Results

Computational fluid dynamics simulations showed three distinct flow types ranging from simple to complex. Virtual angiographic images showed good agreement with images from conventional angiography for all three aneurysms with analogous size and orientation of the inflow jet, regions of impaction, and flow type. Large intra-aneurysmal vortices and regions of outflow also corresponded between the images.

Conclusions

Patient-specific image-based computational models of cerebral aneurysms can realistically reproduce the major intra-aneurysmal flow structures observed with conventional angiography. The agreement between computational models and angiographic structures is less for slower zones of recirculation later in the cardiac cycle.

Key Words: Cerebral aneurysms, rotational angiography, computational fluid dynamics, cerebral angiography