B1-Mapping with the Transient Phase of SSFP

Carl Ganter¹, Marcus Settles¹, Klaus Scheffler², Oliver Bieri²

In rapid SSFP sequences, the approach toward dynamical equilibrium (transient phase) typically consists of a smooth decay and a superimposed damped oscillation. Recent theoretical studies for the FID signal of unbalanced SSFP showed that the frequency of the latter is closely connected to the actual flip angle α and depends only weakly on tissue parameters. In this work, we show that fast and accurate B1-mapping, based on a frequency analysis of the transient phase of SSFP, can be implemented in a conceptually simple and flexible manner.