Conductivity imaging of animal and human body using 3T magnetic resonance electrical impedance tomography (MREIT)

Magnetic resonance electrical impedance tomography (MREIT) aims to produce cross-sectional images of conductivity distributions inside animal and human subjects. In this study, we validate its feasibility by performing conductivity imaging experiments of animal and human bodies. We attached four carbon-hydrogel electrodes on the imaging area and placed the imaging object inside our 3T MRI scanner. We injected imaging currents in a form of short pulses into a chosen imaging area, of which timing was synchronized with an MRI pulse sequence. Obtaining images of induced magnetic flux density distributions inside the imaging object, we reconstructed conductivity images using the single-step harmonic B _z algorithm. Reconstructed conductivity images of the canine heart, kidney, prostate, and other organs exhibit unique contrast information which is hardly observed in other imaging modalities. The conductivity images of the human lower extremity well distinguished different parts of the subcutaneous adipose tissue, muscle, crural fascia, intermuscular septum and bone. Providing cross-sectional conductivity images, MREIT may deliver unique new diagnostic information in its future clinical studies.