System and method for magnetic resonance imaging using shaped radio frequency pulses

Abstract

A system and method are described for MRI excitation pulse design. The system can include a magnetic system that produces a main magnetic field over a portion of a subject for MRI imaging. The system can also include an RF system configured to transmit and receive an RF or B1+ field across at least a target region within the subject. The system may further include a gradient system configured to spatially encode the B1+ field using a gradient waveform. The system may also include a control system, which can be configured to control the RF system in order to generate an RF excitation pulse. The excitation pulse includes freely-shaped RF waveforms, gradient waveforms and, potentially shim array waveforms, selected by penalizing deviation of a flip-angle from a target distribution in order to achieve a target magnetization profile. The method can be applied to 3D and 2D slice-selective excitation and refocusing.

Dependencies are inferred from the claim text.