A Low-Power, Offline Prescreen to Detect and Suppress Dangerous Currents

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

We demonstrate the feasibility of offline screening of patients for dangerous interactions between imaging fields and implanted wires. We show that using a standard imaging coil outside the MRI environment, and only a few milliwatts of power, we can measure the impedance spectra of the coil, which shows characteristic distortions in the case of a resonant interaction. Furthermore, we show that this same spectral information can be used to determine the phasing of the drive ports which can null the induced current during a subsequent scan.