Cramér Rao bound analysis of joint B1/T1 mapping methods in MRI
In MRI, RF field inhomogeneity (B<inf>1</inf>) and relaxation effects (T<inf>1</inf>) significantly affect both B<inf>1</inf> and T<inf>1</inf> mapping. Simultaneous joint estimation of both B<inf>1</inf> and T<inf>1</inf> has the potential to greatly improve both B<inf>1</inf> and T<inf>1</inf> estimation. This paper analyzes the Cramér Rao Bound for joint B<inf>1</inf>, T<inf>1</inf> estimation using common B<inf>1</inf> and T<inf>1</inf> pulse sequences. This analysis aids choosing pulse sequences and parameters given desired levels of B<inf>1</inf> and T<inf>1</inf> accuracy and the inherent trade off between the two mappings.