Imaging electric conductivity with MRI

The electric conductivity of human tissue could be used as an additional diagnostic parameter or might be helpful for the prediction of the local SAR during MR measurements. In this study, the approach "Electric Properties Tomography" (MR-EPT) is applied, which derives the patient's electric conductivity using a standard MR system. To this goal, the spatial transmit sensitivity distribution of the applied RF coil is measured. This sensitivity distribution represents the positive circularly polarized component of the magnetic field. It can be post-processed utilizing Faraday's and Ampere's law, yielding an estimation of the spatial distribution of the patient's electric conductivity. Thus, MR-EPT does not apply externally mounted electrodes, currents, or RF probes. In this study, phantom experiments underline the principle feasibility of MR-EPT. Furthermore, initial conductivity measurements in the brain allow distinguishing cerebro-spinal fluid from the surrounding grey and white matter.