(A) Schematic architecture of the neural network. A
U-Net–based generator (blue) synthesizes a T2 map estimate from
three anatomic scans. Patch-based discriminators (red) compare the
synthesized (Synth) map to a true T2 map corresponding to the same
anatomy. Loss functions (green), consisting of a combination of sigmoid
cross-entropy and L1 loss, were computed and used to update the
generator and the two discriminators. (B) Schematic
illustration of the U-Net, taking the double-echo in steady-state (DESS)
and turbo spin-echo (TSE) scans as input and producing an estimated T2
map as output. Cor = coronal, ReLU = rectified linear unit, Sag =
sagittal.