Feasibility Study of MREIT in Clinical Applications

Introduction Several in vitro studies have shown that the electrical impedance of malignant tissues is significantly higher than those of normal and benign tissues. Therefore, impedance imaging has the potential as a diagnostic tool in cancer. Magnetic Resonance Electrical Impedance Tomography (MREIT) is a technique that is used for imaging impedance distribution inside an object noninvasively [1]. In MREIT, an external current is injected into the object and magnetic field perturbations due to this current are measured. Impedance images can be formed from these measurements using various reconstruction algorithms. In MREIT, increasing injected current results in higher SNR in the measurements, leading to improved quality of the reconstructed images. However, safety regulations impose a limit on the total current that can be injected into a patient [3, 4]. Although a human study with 9mA is reported [2], the injected currents in MREIT should not exceed a few hundred microamperes.