On the frequency dependence of electrical conductivity

Electric conductivity depends on the frequency of the probing electric field. The impact of the frequency differs between human tissue types, e.g., it is lower for body fluids than for cellular tissue types. The upcoming mid-field systems suggest to investigate this frequency dependence with MRI. This study investigated two phantoms, with and without cellular structure, to explore the frequency dependence of conductivity using “Electrical Properties Tomography”. The conductivity results obtained at three different Larmor frequencies were used to estimate the conductivity at lower frequencies in the range of kHz as required for, e.g., EEG source localization.