| The B1 inhomogeneity is well known to be a source of artifact in high field MRI, and requires the use of multiple-channel parallel transmit coil to reduce the artifact by making either the B1 distribution (static shimming) or the flip angle distribution (dynamic shimming) as uniform as possible. The former method complies with most imaging sequences, albeit limited to a small ROI for a reasonable number of channels, the latter usually implemented with a k-space spoke trajectory, offers more degrees of freedom and might cover an entire head slice or volume, but appears as a very specific technique in which the pulses design could not be easily and fully automated. We present here an intermediate and versatile approach to mitigate B1 inhomogeneity based on the principle of complementary images superposition (CIS) while maximizing the signal to noise ratio (S/N). Both simulation and experimental results are reported in this abstract for a 7 T MRI scanner. |
