Figure 5.

T₁T1W MRI predictions generated from 3 independent test patients using UNet, UNet++ and Cycle-GAN models (panel A: patient 1, panels B–E, G: patient 2, panel F: patient 3). Red box: Predictions from pelvic slices with relatively fixed geometries including the bones demonstrate sharp boundaries between anatomical structures, with visually superior results for the Cycle-GAN architecture (panels A, F). Green box: The superior resolution of the Cycle-GAN architecture is further exemplified in slices with deformable structures such as the bowel loop (panels F, G). In highly deformable regions, minor contrast disparity in anatomical structures can be observed in the synthetic MRI; examples include prediction of bladder (red arrows in panel C), lower gastrointestinal region (red arrows in panels D, E) and rectum (blue arrows in panels C, D).