Design of a more easily shimmable gradiometric coil using linear programming

Abstract

Magnetic particle imaging (MPI) is a tracer imaging modality that detects superparamagnetic iron oxide nanoparticles (SPIOs), enabling sensitive, radiation-free imaging of cells and disease pathologies. The arbitrary waveform relaxometer (AWR) is an indispensable platform for developing magnetic nanoparticle tracers and evaluating tracer performace for magnetic particle imaging applications. One of the biggest challenges in arbitrary waveform excitation is direct feedthrough interference, which is usually six orders of magnitude larger than the signal from magnetic nanoparticles. Direct feedthrough is often mitigated with a gradiometric cancellation coil which requires extremely precise placement in order to achieve adequate decoupling from the transmit excitation coil. This work will showcase a coil design of a transmit coil that meets excitation capability requirements with an order of magnitude more forgiving mechanical tolerance.