Extraction of conductivity and permittivity using magnetic resonance imaging

Modeling the effects of RF penetration in magnetic resonance (MR) imaging requires a knowledge of the local values of conductivity and permittivity. The inverse problem of determining the electric properties of the material under investigation using the MR images themselves has not previously been addressed. The authors review such an approach for the heterogeneous layer model and examine the parameter sensitivity to geometry and signal-to-noise ratio. For a few-layer system, it is within the realm of present day MR systems to extract the electric properties to within 10% or better. Knowledge of the electrical properties will then allow a better prediction of the RF penetration and power deposition at high fields.