Utilizing multiple scale models to improve predict

Authors: Gregory G Scott Susan S Margulies Brittany Coats

Publish Date: 2015/11/19

Volume: 15, Issue: 5, Pages: 1101-1119

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Abstract

Traumatic brain injury TBI is a leading cause of death and disability in the USA To help understand and better predict TBI researchers have developed complex finite element FE models of the head which incorporate many biological structures such as scalp skull meninges brain with gray/white matter differentiation and vasculature However most models drastically simplify the membranes and substructures between the pia and arachnoid membranes We hypothesize that substructures in the pia–arachnoid complex PAC contribute substantially to brain deformation following head rotation and that when included in FE models accuracy of extraaxial hemorrhage prediction improves To test these hypotheses microscale FE models of the PAC were developed to span the variability of PAC substructure anatomy and regional density The constitutive response of these models were then integrated into an existing macroscale FE model of the immature piglet brain to identify changes in cortical stress distribution and predictions of extraaxial hemorrhage EAH Incorporating regional variability of PAC substructures substantially altered the distribution of principal stress on the cortical surface of the brain compared to a uniform representation of the PAC Simulations of 24 nonimpact rapid head rotations in an immature piglet animal model resulted in improved accuracy of EAH prediction to 94  sensitivity 100  specificity as well as a high accuracy in regional hemorrhage prediction to 82–100  sensitivity 100  specificity We conclude that including a biofidelic PAC substructure variability in FE models of the head is essential for improved predictions of hemorrhage at the brain/skull interface

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