1University of Toronto, Toronto, ON, Canada, 2Massachusetts General Hospital, Charlestown, MA, United States, 3Sunnybrook Health Sciences Centre, Toronto, ON, Canada
Long implanted wires, such as deep brain stimulation (DBS) implants, are
subject to radiofrequency (RF) heating during MRI. In previous work, RF shimming was used to
tailor the electric and magnetic fields creating optimal excitation and minimal
heating in a uniform cylindrical medium with a single, straight, implanted copper
wire at 3T. This work extends the
methodology to a complex, heterogeneous head model with one or two implanted,
curved copper wire(s). A substantial
improvement in both B1+-field homogeneity and E-field
reduction is achieved when compared with a transmit/receive birdcage coil in
both the single wire and bilateral wire case.
