Shear shock waves observed in the ex-vivo brain

摘要

Head injury biomechanics has been guided by measurements of accelerometers attached to the skull, which provides a partial and indirect estimate of brain motion because the internal deformation of the brain is far more complex than the rigid motion of the skull. Attempts to measure the in situ nonlinear brain mechanics with imaging methods (MRI, CT) have lacked the penetration, frame rate, or motion detection accuracy to capture the rapid brain motion associated with nonlinear transient events during traumatic injury. Here we present a high frame-rate (6200 images/second) ultrasound imaging method that can accurately (<;1 μm) measure the internal brain motion during the rapid transient events associated with a mild impact in an ex vivo porcine brain. It is shown that shear shock waves are generated in the brain even under low impact conditions.