I am doing fieldmapless SDC correction with SynBOLD-DisCo (paper, github). SynBOLD-DisCo creates a “synthetic, undistorted” BOLD image, which is then used as an input to top-up to generate a distortion-corrected BOLD image.
As you can see, the synthetic image looks fine.
However, the final output has streaks at the front of the brain
and with further investigation we see that this corresponds to streaks in the top-up image
and in the top-up field coefficients.
Has this happened to anyone before?