Abstract: Various methods and systems are provided for correcting k-space trajectories. In one embodiment, a system comprises a coil configured to generate a magnetic field, a plurality of magnetic field probes positioned at the coil and configured to measure the magnetic field, and a controller communicatively coupled to the plurality of magnetic field probes and including instructions stored in non-transitory memory that when executed cause the controller to: receive measurements of the magnetic field from the plurality of magnetic field probes; calculate corrections to positions of acquired magnetic resonance signals in spatial-frequency space based on the received measurements; apply the corrections to the positions to generate corrected magnetic resonance signals; and reconstruct an image from the corrected magnetic resonance signals. In this way, image artifacts caused by eddy currents can be reduced.

Abstract: A method includes heating a MRI shim with a heater to reduce a temperature rise per unit of time during a gradient operation of a MRI system.

Abstract: A zero boiloff cryogen cooled recondensing superconducting magnet assembly including superconducting magnet coils suitable for magnetic resonance imaging including a cryogen pressure vessel to contain a liquid cryogen reservoir to provide cryogenic temperatures to the magnet coils for superconducting operation; a vacuum vessel surrounding the pressure vessel and spaced therefrom; a first thermal shield surrounding and spaced from the pressure vessel; a second thermal shield surrounding and spaced from the first thermal shield and intermediate the vacuum vessel and the first shield; a cryocooler thermally connected by a first and a second thermal interface to the first and second thermal shields, respectively; a recondenser positioned in the space between the pressure vessel and the first thermal shield and thermally connected by a thermal interface to the cryocooler to recondense, back to liquid, cryogen gas provided from the pressure vessel; and means for returning the recondensed liquid cryogen the pressure