IMPROVED T1-WEIGHTED 2-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 evoluti on in magnetization-prepared gradient-echo (MP-GRE) imaging with varia ble flip angles has been applied to two-dimensional (2D) MP-GRE imagin g of the abdomen. The technique was analyzed by using theoretical mode ls and was implemented on a standard 1.5-T whole-body imager with a se gmented acquisition. Theoretical models predicted that the variable-fl ip-angle 2D MP-GRE sequence would increase liver-spleen signal differe nce-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 pha se encoding, and the fast low-angle shot sequence, respectively. Exper imental measurements supported the theoretical predictions.