Patent ID: 8896308
Filing Date: 2014-11-25
Classification: A61N,G01R

Abstract:
1. A self-shielded gradient coil assembly for a horizontal open magnetic resonance imaging system (MRI) used in conjunction with an instrument, the open MRI having a longitudinal axis and a first magnet and a second magnet separated by a gap, the instrument being located within a portion of the gap, the gradient coil assembly comprising: a supporting structure having a first supporting structure portion and a second supporting structure portion, the first supporting structure portion mounted inside of the first magnet and the second supporting structure portion mounted inside of the second magnet; a plurality of shielding coils disposed within each supporting structure portion; a plurality of primary gradient coils disposed within each supporting structure portion between the plurality of shielding coils and the longitudinal axis; and electrical connections between the plurality of primary gradient coils and the plurality of shielding coils arranged so that the electrical connections are located a sufficient distance from the gap to reduce eddy currents induced in the instrument, wherein the plurality of shielding coils and the plurality of primary gradient coils are arranged so that a first concentration of the shielding coils and the primary gradient coils in a first section near the gap is less than a second concentration of the shielding coils and the primary gradient coils in a second section, and wherein the first section is disposed between the gap and the second section.