Current treatments of cerebral aneurysms are imperfect, and aneurysmal hemodynamics is an important factor in treatment failure. The identification of hemodynamic factors that influence treatment success could predict outcome. Published studies show that the hemodynamic environment of aneurysms changes after treatment, and there is limited retrospective evidence that the degree of change affects treatment success. However, previous hemodynamic calculations did not have access to patient-specific measurements of blood flow, which substantially reduced their accuracy. In addition, no prospective studies of the predictive value of post-treatment aneurysm hemodynamics have been done.