Improved T1-weighted two-dimensional MP-GRE imaging of the liver with variable flip angles for shaping the signal evolution.

The recently introduced method of shaping the transient signal evolution in magnetization-prepared gradient-echo (MP-GRE) imaging with variable flip angles has been applied to two-dimensional (2D) MP-GRE imaging of the abdomen. The technique was analyzed by using theoretical models and was implemented on a standard 1.5-T whole-body imager with a segmented acquisition. Theoretical models predicted that the variable-flip-angle 2D MP-GRE sequence would increase liver-spleen signal difference--to-noise ratios by 290%, 110%, and 160% compared with a 2D MP-GRE sequence with a flip angle of 10 degrees and sequential phase encoding, a 2D MP-GRE sequence with a flip angle of 30 degrees and centric phase encoding, and the fast low-angle shot sequence, respectively. Experimental measurements supported the theoretical predictions.