Measurement of electrical properties of biological tissue at radio frequencies using magnetic resonance imaging

Image shading in high-field magnetic resonance imaging (MRI) due to radio-frequency (RF) wave propagation effects in biological tissue can be used to measure the electrical conductivity and relative permittivity of tissue in vivo. We describe a method to extract electrical properties of biological tissue from RF-shaded MR images without an explicit RF field mapping. The method is demonstrated on a meat sample and in the brain of a normal volunteer.