ausblenden:
Schlagwörter:
Anisotropy; Conductivity; FEM; Animal model; Simulation; EEG
Zusammenfassung:
The aim of this study was to quantify the influence
of the inclusion of anisotropic conductivity on EEG source
reconstruction. We applied high-resolution finite element
modeling and performed forward and inverse simulation with
over 4000 single dipoles placed around an anisotropic volume
block (with an anisotropic ratio of 1:10) in a rabbit brain. We
investigated three different orientation of the dipoles with
respect to the anisotropy in the white matter block. We found a
weak influence of the anisotropy in the forward simulation on
the electric potential. The relative difference measure (RDM)
between the potentials simulated with and without taking into
account anisotropy was less than 0.009. The changes in
magnitude (MAG) ranged from 0.944 to 1.036. Using the
potentials of the forward simulation derived with the
anisotropic model and performing source reconstruction by
employing the isotropic model led to dipole shifts of up to 2
mm, however the mean shift over all dipoles and orientations of
0.05 mm was smaller than the grid size of the FEM model (0.6
mm). However, we found the source strength estimation to be
more influenced by the anisotropy (up to 7-times magnified
dipole strength).
