RF Pulse Design for MRI Off-Resonance Mitigation

The patent replaces the mechanical shimming system with a computational approach. Instead of relying on physical shim coils to correct field inhomogeneities, the system uses computer-based pulse design algorithms that calculate and apply phase corrections to RF pulses, substituting hardware-based field adjustment with software-based signal processing.

The patent changes the parameters of RF pulses (amplitude, phase, duration) through computational optimization to compensate for magnetic field inhomogeneities. By modifying pulse parameters rather than physical field parameters, the system achieves field uniformity effects without requiring complex shimming hardware.

The patent employs dynamic RF pulse sequences where pulse parameters are continuously adjusted during the sequence to track and compensate for off-resonance effects. This dynamic adaptation allows for shorter pulse durations while maintaining excitation completeness, as the system actively corrects phase errors rather than relying on extended pulse lengths.

The patent uses periodic refocusing pulses with optimized timing and phase relationships to maintain excitation completeness over shorter durations. By strategically timing these periodic pulses, the system achieves complete excitation coverage without requiring continuously extended pulse sequences.

The patent replaces hardware-based field correction systems with computational pulse design. Instead of using complex shim coils or field-adjustment hardware, the system uses computer-calculated RF pulse parameters to compensate for off-resonance effects, substituting mechanical field adjustment with digital signal processing.

The patent implements self-correcting RF pulses that automatically compensate for off-resonance effects through embedded phase modulation. The pulses are designed to inherently counteract their own susceptibility-induced phase errors, making the system self-correcting without requiring external hardware intervention.