US 11,698,430 B2
Eddy current mitigation systems and methods
Hadrien A. Dyvorne, New York, NY (US); Cedric Hugon, Guilford, CT (US); Rafael O'Halloran, Guilford, CT (US); and Laura Sacolick, Guilford, CT (US)
Assigned to Hyperfine Operations, Inc., Guilford, CT (US)
Filed by Hyperfine, Operations, Inc., Guilford, CT (US)
Filed on Aug. 14, 2020, as Appl. No. 16/994,005.
Claims priority of provisional application 62/887,212, filed on Aug. 15, 2019.
Prior Publication US 2021/0048498 A1, Feb. 18, 2021
Int. Cl. G01R 33/565 (2006.01); G01R 33/58 (2006.01)
CPC G01R 33/56518 (2013.01) [G01R 33/58 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A method for operating a magnetic resonance imaging (MRI) system by generating a target gradient field in accordance with a pulse sequence, the pulse sequence comprising a gradient waveform associated with the target gradient field, the method comprising:
compensating for presence of eddy currents during operation of the MRI system at least in part by correcting the gradient waveform using a first nonlinear function of a characteristic of the gradient waveform to obtain a corrected gradient waveform;
determining a shifted B0 magnetic field strength waveform using the corrected gradient waveform and a second nonlinear function describing effects of an amplitude of the gradient waveform on a B0 magnetic field of the MRI system;
determining information indicative of variation of an operating frequency of an RF coil of the MRI system over a duration of the pulse sequence based on the shifted B0 magnetic field strength waveform, the information configured to govern a transmit and/or receive frequency of the RF coil while the MRI system is operated in accordance with the pulse sequence; and
operating the MRI system in accordance with the corrected gradient waveform to generate the target gradient field.