Estimating mechanical brain tissue properties with simulation and registration

Abstract

In this work a new method for the determination of the mechanical properties of brain tissue is introduced. Young's modulus E and Poisson's ratio v are iteratively estimated based on a finite element model for brain shift and on the information contained in pre- and intraoperative MR data after registration. In each iteration, a 3D dataset is generated according to the displacement vector field resulting from a numerical simulation of the intraoperative brain deformation. This reconstruction is parametrized by elastic moduli of tissue. They are automatically varied in order to achieve the best correspondence between the grey value distribution in the reconstructed image and the intensity entropy in the MR image of the brain undergoing deformation. This work contributes to the difficult problem of defining correct mechanical parameters to perform reliable model calculations of brain deformation. Proper boundary conditions that are crucial in this context are also addressed. © Springer-Verlag Berlin Heidelberg 2004.