Patent ID: 8729899
Filing Date: 2014-05-20
Classification: G01R

Abstract:
1. A magnetic resonance imaging (MRI) system magnet comprising: at least one main electromagnet winding disposed within a first radius of the magnet and configured to provide a magnetic field directed along an axial direction within the magnet and which also produces fringe magnetic fields outside said magnet; at least one bucking electromagnet winding disposed within a second radius, larger than said first radius, of the magnet and configured to provide self-shielding magnetic fields that substantially reduce fringe magnetic fields outside said magnet produced by said main electromagnet winding, the combination of magnetic fields produced by both the main and bucking electromagnet windings inside the magnet conforming to MRI requirements within at least an imaging volume; said main and bucking electromagnet windings being configured so as to create a net fringe field outside said magnet within the range of 50-100 gauss at a distance within a range of 3-5 meters axially and 2-3 meters radially from a center of the magnet.