Contrast in Visualized Currents Using Reverse Polarization and Pre-Spoiling Twister Gradients

Christopher W. Ellenor¹, Pascal P. Stang¹, John M. Pauly¹, Greig C. Scott¹

In a simple phantom study, we compare the use of two techniques for the visualization of dangerous currents in implanted wires. The phantom is imaged using the reverse-polarization method, twister gradients, or a combination of the two, and the conspicuity of the current-carrying wire is determined by measuring image contrast. We find that gradient spoiling can achieve results similar to reverse polarization. We also employ a numerical model to attempt to extrapolate these results to 3T and 7T systems, where we find very similar results at 3T, and a reduction in effectiveness of reverse polarization at 7T.