Bipolar Flip Angle Modulated Chemical Shift Encoded Imaging Enabled with Gradient Impulse Response Function

Motivation: Unipolar FAM enables motion robust CSE imaging but would benefit from shorter echo and scan times to account for PDFF quantification with a high R2*. Goal(s): We aim to develop a CSE sequence with shorter TE and scan time with robust PDFF quantification within patients. Approach: Gradient impulse response function (GIRF) was used to account for gradient-related phase errors that complicate PDFF measurements in bipolar 2D-FAM. Results: Bipolar 2D-CSE with GIRF correction enabled accurate PDFF measurement with similar results to 3D-CSE and better performance than unipolar 2D-CSE at high R2*. Impact: This study explores the application of GIRF to enable bipolar 2D-FAM for PDFF quantification. Results are comparable to conventional 3D-CSE and unipolar 2D-FAM, but yield scan time reduction, increase in R2* dynamic range, and shorter ∆TE.