1Physics and Astronomy, Western University, London, Ontario, Canada; 2Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada
Active magnetic shim coils, used to correct field inhomogeneities caused by susceptibility differences between tissue interfaces, are typically composed of sets of cylindrical layers, with each layer producing a magnetic field profile of a particular spherical harmonic. A radically different approach to shimming is to dynamically and adaptively control the flow of current over a given surface. This could be achieved with the use of a network of metal-oxide-semiconductor field-effect transistors (MOSFETs). In this work, we present computer simulations demonstrating the benefits that a supplementary, region specific shim coil utilizing this approach can provide, and experimental results of a proof-of-principle prototype.