SIMULTANEOUS MULTISLICE MRI WITH RANDOM GRADIENT ENCODING

摘要

Systems and methods for simultaneous multislice (“SMS”} magnetic resonance imaging (“MRI”}, in which a random blip gradient encoding scheme is utilized to impart a different phase to each of a plurality of different slice locations. Because of the random blip gradient encoding, the amount of the imparted phase is randomized for each phase encoding step in a Cartesian k-space trajectory. This data acquisition strategy leads to incoherent aliasing artifacts across the simultaneously excited slices. Images of the individual slices can be reconstructed using a compressed sensing framework.

主权项

1. A method for producing a plurality of images of a subject with a magnetic resonance imaging (MRI) system, the steps of the method comprising:
a) directing an MRI system to perform a pulse sequence comprising:
applying a radio frequency (RF) excitation field to a portion of a subject that includes a plurality of slice locations, the plurality of slice locations including a current slice location and at least one adjacent slice location, the RF excitation field exciting spins in the plurality of slice locations;establishing at least one readout magnetic field gradient along a frequency-encoding direction following the application of the RF excitation field in order to form echo signals;sequentially producing a plurality of slice-encoding magnetic field gradient blips along a slice-encoding direction while the at least one readout magnetic field gradient is established, each sequential slice-encoding magnetic field gradient blip having a randomly assigned magnitude such that a random phase shift related to the randomly assigned magnitude is imparted to the formed echo signals; b) acquiring data with an array of RF receiver coils by sampling the formed echo signals; and c) reconstructing at least one image for each of the plurality of slice locations from the data acquired in step b).