Аннотация:Application of computational fluid dynamics in intracranial aneurysms (IA)assessment is one of the most relevant trends in the modern 2D/3D image processing and mathematical modelling in medicine. The choice of treatment scheme for patients with IA is defined by the risk relation of a conservative treatment and intraoperational risks of different surgical approaches. The aneurysm rupture risk assessment is still an unresolved issue, however it is well known that risk evaluation requires not only morphometric parameters but also hemodynamic characteristics. Unfortunately, the last ones cannot be estimated by the current in vivo diagnostic methods. This chapter is dedicated to the applicability of patient-specific 3D reconstructions based on CT angiography followed by CFD modelling with respect to patient’s blood flow velocity parameters.