Patent ID: 8228061
Filing Date: 2012-07-24
Classification: G01R

Abstract:
1. A non-transitory computer-readable medium storing computer-executable instructions that when executed by the computer cause the computer to perform a method which mitigates the effects of off resonance angle, in steady-state coherent MRI sequences that image an object, the method comprising: accessing a B0 map and a coil sensitivity profile associated with a magnetic resonance imaging (MRI) apparatus that is configured to produce a steady-state coherent MRI sequence in order to image an object, the MRI apparatus being configured with a multi-channel transmission array having independently and individually controllable transmission channels; computing transmission control parameters associated with one of excitation and de-excitation for individual transmission channels of the multi-channel transmission array as a function of the B0 map and the coil sensitivity profile, where the transmission control parameters are configured to facilitate controlling the multi-channel transmission array to use a single dimensional radio frequency (RF) pulse in order to create a spatially varying phase profile; providing the control parameters to one or more of, the MRI apparatus, and an MRI simulation; controlling the MRI apparatus in order to transmit RF energy comprising a single dimensional pulse through two or more of the individual transmission channels of the multi-channel transmission array according to the transmission control parameters; identifying an off-resonance angle produced by the steady-state coherent MRI sequence, where the off-resonance angle defines phase accumulated by spins in a voxel in the MRI imaged object at the end of a repetition time (TR); and providing the off-resonance angle to one or more of, the MRI apparatus and an MRI simulation of an MRI imaged object; compensating for phase accumulation and off-resonance angle produced as a result of the steady-state coherent MRI sequence by producing a multiple pulse mitigation modification to the steady-state coherent MRI sequence where the modification comprises modifying one or more of, the amplitude, and the phase of one pulse of the multiple pulse mitigation sequence as a function of the identified off-resonance angle.