SC/Tetra Used to Predict Aneurysm Risk
In a study of patients with unruptured cerebral aneurysms at the Jichi Medical College in Japan, some possessed enlarged and/or deformed aneurysms. A major concern for patients with enlarged and/or deformed aneurysms is the potential impact of induced stresses on the blood vessel walls caused by the blood flow. Unfavorable flow conditions (or stress) can lead to future rupture and may warrant immediate medical treatment.
Researchers at the Medical College used Cradle SC/Tetra Computational Fluid Dynamics (CFD) software to analytically simulate the effects of blood flow on the aneurysm wall stresses. Cerebral blood vessels and aneurysms exhibit complex morphological features making them difficult, expensive, and time-consuming to physically simulate. Using SC/Tetra to analytically simulate blood flow is a reasonable alternative.
- The robustness and versatile functionality of the SC/Tetra pre-processor greatly facilitated geometry and mesh generation of the three-dimensional blood vessel structures from medical images of the cerebral aneurysm. While pre-processing was the most time consuming part of the process, results were sufficiently encouraging to expect that pre-processing times can one day be reduced from hours to minutes.
- Upon solution of the blood flow field, the calculated three-dimensional structures of the enlarged and/or deformed aneurysm were compared with those of the pre-images in order to reveal the site(s) of deformity and enlargement.
- Many different cases were run and analyzed enabling deduction of general trends and universal patterns from the collective set of cases.
- The analysis revealed that sites of the aneurysm appeared to be extremely low in wall shear stress but high in shear gradient. This potentially suggests that the kinetics or dynamics of the moving fluid, in combination with morphological analysis, can predict the existence of a fragile aneurysm that is susceptible to rupture.
The successful characterization of aneurysm behavior, from the clinical application of CFD, continues to demonstrate the value of computational simulation.