Optimized interferometric encoding of presaturated TurboFLASH B1-mapping for pTx at 7T MRI: Application to T1-mapping in the spinal cord

One of the best solutions to B1 inhomogeneities observed at ultra-high field MRI is to use parallel transmit techniques (pTx). However, fast and accurate knowledge of the B1+ is required. The presaturated TurboFLASH (satTFL)-based B1-mapping sequence, with interferometric encoding, has shown great promise due to its speed and reliability, but it was observed that its performance may drop when used with unconventional radiofrequency coils and applications. In this study, a novel optimization of the interferometric encoding is presented and applied to cervical spinal cord MRI at 7T. The impact of having improved B1-maps is evaluated on pTx MP2RAGE-based T1-mapping.