Optimized ultrahigh field parallel transmission workflow using rapid presaturated TurboFLASH transmit field mapping with a three-dimensional centric single-shot readout
Dario Bosch, Jonas Bause, Ole Geldschläger, Klaus Scheffler
Abstract
Purpose
To evaluate the usage of 3D presaturated TFL for \bplus and \bnull mapping on 1Tx- and pTx-systems.
Methods
B1+ maps recorded with 3D satTFL were compared to maps from three other 3D B1+ mapping sequences in an agar phantom. Furthermore, individual-channel B1+ maps of 18 human subjects were recorded with 3D satTFL using B1+ interferometry. A neural network was trained for masking of the maps.
Results
Out of the sequences compared satTFL was the only one with a mapping range exceeding well over 90˚. In regions with lower flip angles there was high correspondence between satTFL and AFI. DREAM and DAM also showed high qualitative similarity, however the magnitude differed from the other two measurements. The individual-channel \bplus maps were successfully used for pTx pulse calculation in a separate study.
Conclusion
3D satTFL can record high-quality B1+ maps with a high dynamic range in a short time. Correspondence with AFI maps is high, while measurement duration is reduced drastically.