Silent T<sub>1</sub> mapping using the variable flip angle method with B<sub>1</sub> correction
Emil Ljungberg, Tobias Wood, Ana Beatriz Solana, Shannon Kolind, Steven Williams, Florian Wiesinger, Gareth J. Barker
Abstract
Purpose To compare the silent rotating ultrafast imaging sequence (RUFIS) to a traditional Cartesian spoiled gradient‐echo (SPGR) acquisition scheme for variable flip angle (VFA) mapping. Methods A two‐point VFA measurement was performed using RUFIS and Cartesian SPGR in a quantitative phantom and healthy volunteers. To correct for errors, a novel silent magnetization prepared map acquisition (SIMBA) was developed, which combined with RUFIS VFA allows for a completely silent mapping protocol. Results The silent protocol was found to have comparable repeatability but higher reproducibility in vivo compared to the standard SPGR protocol, and showed no increase in acoustic noise levels above background noise levels compared to a 33 dBA increase for the SPGR acquisition. Conclusions VFA mapping using RUFIS is a feasible alternative to SPGR, achieving silent mapping with comparable acquisition time.