Optimization of the T2-weighted MRI contrast in 0-6-month-old infant brain based on extended phase graph theory

3D T2-weighted MRI using fast spin-echo (FSE) with variable flip angles has been widely for anatomical imaging. However, 3D FSE of infant brains exhibits poor contrast due to the inherently close and rapidly changing T2 relaxation times between white matter and grey matter. Here we proposed an extended-phase-graph-based method to optimize the flip angles in FSE sequence for maximizing the white/grey matter contrast in 0 to 6 month-old infant brains at 3T, based on T2 values acquired from 37 infant brains. Results demonstrated improved relative contrasts in infant brains by 1.6-2 folds at different ages in different regions of interest.