Fig 2:

A 3D multi-pathway multi-echo (MPME) sequence of our own design was used to acquire four signal pathways at 2 different echo times. The numerals indicate the pathway number, from −2^nd to +1^st, and the gray arrows indicate the timing of each signal formation. T_RG1 and T_RG2 define the length of the time interval from the center of the RF pulse to the center of the corresponding readout group, i.e., T_RG is to readout groups what TE would be to individual echoes.