Magnitude image to T1w transformation - fmriprep 21

Hello all,

I am using fmriPrep 21.0.1 to preprocess an fMRI dataset that includes fieldmaps. In this new version, we get a magnitude and fieldmap image in the ‘fmap’ folder.

This magnitude image is in its own space, though, and I would like to get it in T1w space to then get the fieldmap in MNI space (for voxel shift map estimations).

Is the transformation from magnitude to T1w (or magnitude to bold) already estimated somewhere in the work folder? I guess it has to, in order for the fieldmap to be applied, but I couldn’t find it.

Thank you in advance for the help,