Traumatic brain injuries (TBI) caused by impacts to the head represent a serious and continuing public health problem. Protective equipment and procedural controls are widely used to mitigate the risk of injury, yet incidence of mild TBI (mTBI), including concussion remains high. In order to develop effective protective equipment that reduces the risk of injury, complex numerical models of the brain and head are needed. While model development is ongoing, the scarcity of existing empirical test data to validate such models remains a considerable limitation. To date, empirical studies of post-mortem human subjects (PMHS) with limited spatial and temporal resolution of imaging systems have been unable to provide a complete understanding of the motion and deformation of the brain caused by head impacts. Further, error associated with measurement methods may be overlooked due to the conflation of precision with accuracy and mischaracterization of the influence of measurement systems on biological tissue. The aim of this work was to develop a comprehensive methodology for measuring the displacement of discrete brain structures during head impact. Improvements over past studies to embedded tissue target design and placement, perfusion methods, imaging, and post-processing have been made. An advanced high-speed X-Ray system, developed at Carleton University, was used to capture brain motion for two PMHS at 7,500 fps. Custom particle tracking software was used to resolve motion into displacement traces across numerous well-defined brain structures. Embedded target positions were evaluated by neurosurgeons with the use of Magnetic Resonance Imaging (Royal Ottawa Hospital). Motion trends were region dependent, with some regions exhibiting multi-modal displacement. Displacement of discrete structures surrounding the lateral ventricle, including the corpus callosum, was observed and measured, revealing a previously unreported deformation at the earliest moments of impact.
2021-04-07 08:00:00
