Effects of Brain Gyrification on Impact-Induced Strain Measurements with a Preliminary Study on Viable ex vivo Porcine Brain

Traumatic brain injuries can be devastating. In post-mortem brains, injury accumulation has been found at surface depressions; a feature in brains with gyrification. A study into the importance of brain gyrification on impact-induced strain measurements was undertaken. Two surrogates, lacking and possessing gyrification, were impacted at multiple heights and orientations. Radiopaque speckle sheets within the surrogates were used to visualize motion at 7,500 fps via highspeed X-ray radiography. Strain responses between select markers were determined using digital image correlation and particle tracking. The surrogate with gyrification mostly displayed larger strain magnitudes and variations in response patterns compared to the smooth surrogate. Differences in gyrification may contribute to the damage incurred, where models representing human level gyrification may reveal unknown injury information. Additionally, a preliminary study was conducted on ex vivo porcine brain. Large strain values and variations in responses were observed, a trend experienced by the surrogate with gyrification.