Within this project, the development of a methodology for the patient specific analysis of cerebral aneurysms is in focus. Such a cerebral aneurysm is potentially life-threatening. Every year, about 10 out of 100,000 people suffer a spontaneous rupture, with a mortality of 50%. For the patients and their attending physicians, a sensible estimation of the rupture risk and the best strategy of treatment is of great importance. We hypothesize that an analysis based on the individual geometry of an aneurysm, and the predicted biofluidmechanical properties can provide insight into this matter. Here, we especially deal with the segmentation, reconstruction and visualization of aneurysms as well as of the analysis of blood flows.