CEE Seminar -The Brain in Motion: Measurements of Brain Mechanical Behavior in Vivo by MRI

High linear and angular accelerations of the skull can lead to rapid deformation of brain tissue and subsequent traumatic brain injury (TBI), but the precise mechanisms of TBI remain incompletely understood. Computer simulations of head-brain biomechanics offer enormous potential for improved understanding and prevention of TBI. However, simulations must be complemented by biomechanical measurements to parameterize and evaluate the underlying mathematical models. The nonlinear, anisotropic, viscoelastic, heterogeneous character of brain tissue, and the intricate connections between the brain and skull all play important roles in the brain’s response to skull acceleration. While studies of animal brains and ex vivo brain tissue have led to important insights, measurements of the response of the intact human brain are necessary and complementary. On the other hand, efforts to understand the motion of the human brain in vivo are complicated by the fact that it is delicate, hidden, and well-protected by the skull. I will describe MR imaging techniques to characterize brain deformation, estimate brain material properties and stress state, and illuminate the boundary conditions between brain and skull, all aimed at improving the ability to model and simulate TBI.