Principles and Use of Magnetic Resonance Electrical Impedance Tomography in Tissue Electroporation

Abstract

© Springer International Publishing AG 2017. All rights are reserved. Electroporation is a phenomenon caused by externally applied electric field of an adequate strength and duration to cells that results in increase of cell membrane permeability to various molecules which otherwise are deprived of transmembrane transport mechanism. As the membrane electroporation is a consequence of an induced transmembrane potential which is directly proportional to the local electric field, magnetic resonance electrical impedance tomography (MREIT) was proposed for reconstruction of electric field distribution during electroporation. MREIT enables determination of electric field distribution by measuring the electric current density distribution and electric conductivity of the treated subject during application of electric pulses by using MRI scanner and numeric algorithms. MREIT yields an electric field distribution, which is a time average of its altering time course so that all the consequences of conductivity alteration of the treated tissue due to electroporation are not neglected within obtained electric field distribution. Feasibility of this method has been demonstrated by determining electric field distribution during electroporation in silico, in agar phantoms, plant tissues, and animal tissues ex vivo and in vivo. In this chapter, mathematical framework of MREIT and the concept of monitoring electric field distribution are provided together with fundamentals of electrical conductivity imaging. Maps of electric field distribution established during electroporation of various tissues that were obtained by means of MREIT are also included.