Electrical impedance of a medium helps to predict the behavior of electrical currents in a medium. Electrical impedance refers indeed to the “difficulty”, for an electrical current, to spread through the medium. While the first impedance measurements were focused on cardiovascular parameters, techniques are now being applied to the whole body, as electrical impedance present important variations through the human body and could then offer a new source of contrast.

Combining electrical current, magnetic fields, and acoustics in various ways have led to interesting techniques to image this parameter: Electrical Impedance Tomography, Magnetic Resonance Electrical Impedance Tomography, Acousto-Electric Imaging, Lorentz Force Electrical Impedance Tomography and Magneto-Acoustic Tomography. These techniques are detailed in this review.