Cerebral aneurysms develop in about 4 % of western populations and involve the risk of rupture. Blood flow patterns are of interest for understanding the pathogenesis of the lesions for a specific patient. Velocity mapping with phase-contrast magnetic resonance angiography (PC-MRA) is a non-invasive method for in vivo measurements on blood velocity. Based on these, a realistic patient-specific computer model can be generated and the flow field with all hemodynamic parameters can be simulated. As the accuracy of the PC-MRA data and subsequent modeling must be validated, a realistic flow field...