Simulation guidelines for incisions patterns on RF shields

Abstract

A study is made and guidelines are found for optimizing slit patterns in radiofrequency (RF) shields. It is found that the gradient eddy currents can be effectively reduced by 1) placing a small number of azimuthal slits centered on "cold" bands outside of the central region of the RF shield and 2) restrictions on the lengths of the centralized axial slits. A simple "strip" model is presented to help understand the, perhaps counter-intuitive, locations of the azimuthal cuts. Special consideration is given to hybrid MRI systems where there is a gap in the main-magnet and gradient coils. © 2012 Wiley Periodicals, Inc.