Simultaneous estimation of I,,, Rz*, and field map using a multi-echo spiral acquisition

Functional MRI using R; maps may be more quantitative and robust than using T;-weighted imaging. Standard estimation techniques are confounded by magnetic susceptibility and inhomogeneity. Even with standard field corrections, errors in estimation of the field map can persist in the R; and I, maps. In this work, we perform an iterative simultaneous estimation of the field map, R; and I,. The results in simulation and human study show that this method is substantially more accurate in determining these parameters than standard estimation schemes.