Which sequence for correcting fMRI data with topup?

Hello all,

I would like to use FSL’s topup to correct multiband GRE-EPI fMRI data. I reckon that this is not new but I failed to find the answer to this question:

  • What sequences should be acquired with opposite phase encoding directions? Can these be GRE or need to be SE-EPI (b0) with matching parameters?

Thank you in advance,

Glasser et al. write about this in https://www.nature.com/articles/nn.4361 (see the Supplementary Information, Topic 7: "Why Spin Echo Field Maps")