In this area, with the techniques we have developed for patient-specific computer modeling of cerebral aneurysms, we are working with our surgeon collaborators with far more computer modeling power than we had before. We will focus on doing correlation studies for determining why some aneurysms rupture and some do not, designing and computer-testing surgical remedies for altering the blood flow patterns in aneurysms, and carrying out patient-specific computations for determining the hemodynamic forces on the arterial walls. There are still more computer modeling challenges that need to be addressed, including better structural and material modeling of the arterial and aneurismal walls, better acquisition of the patient-specific blood velocity data, and better downstream modeling.