EPI to T1 registration visualization

I was wondering what is the functional image that is used to visualize the EPI to T1 registration results? I ask because the image below shows very strong slice effect. But when I check the preprocessed fMRI data they look fine… I use fmriprep 1.0.12.


We estimate a reference image from the first few volumes.


This looks like a spin history effect.

To quote myself:


Just to mention that we are using nearest neighbor in this interpolation, to make those artifacts more obvious.

When resampling for analysis purposes, we use lanczos, which should introduce a certain degree of smoothing between slices.