Magnetic resonance imaging of electrical conductivity in the human brain

Spatial distribution of anisotropic conductivity of the human brain was obtained using magnetic resonance imaging. The fast compo- nent of diffusion was estimated from the relation between the b-factor and the signal intensity of magnetic resonance images. Estimation of conductivity is based on the proportionality between conductivity and the diffusion coefficient of water. The gray matter did not have a clear dependence of conductivity on direction. In some regions in the white matter such as the internal capsule and the corpus callosum, conductivity exhibited high anisotropy. This method has potential applications in current source estimations of electroencephalography (EEG) and magnetoencephalography (MEG).