Self-Correction of B0 Field Drift and k-space Trajectory Errors in Alternating Unbalanced SSFP for Robust R2 and R2’ Mapping

Motivation: Accurate estimation of R2 and R2' provides insights into physiologic and functional states of tissues. Goal(s): To investigate the feasibility of self-correction of B0 field drift and radial trajectory errors in the nonbalanced SSFP-based R2 and R2' mapping technique. Approach: The inherent phase characteristics of the alternating nonbalanced SSFP are utilized, enabling self-correction of B0 field drift and k-space trajectory errors. Results: In both phantom and brain scans, accuracy of parametric maps were enhanced with the self-correction of the two types of image artifacts. Impact: The proposed method, which mitigates artifacts from B0 drift and trajectory mismatch in a self-correction manner, may prove to be a useful means in a wide range of neuroimaging studies seeking rapid and accurate quantifications of R2 and R2'.