Impedance magnetic resonance imaging with external AC field added to main static field

This paper addresses the feasibility for visualization of electrical impeda nce distributions based on magnetic resonance imaging (MRI). By the previou sly proposed method, electrical impedance distribution was visualized. Howe ver obtained images were often associated with artifacts in the directions of phase-encoding and reading-out. In this paper, we propose a new method t o eliminate the artifacts by triggering the added external AC field, which is parallel to the main static field. By this method, one can visualize ele ctrical properties of living organisms noninvasively and in principle, at a n arbitrary frequency. The phantom experiments have been carried out tot ve rify the concept of the shielding effects of induced eddy currents in the s ubject on spin precession and to figure out methodological details of trigg ering using an MRT system of 7.05-T with a bore size of 183-mm in diameter.