Dear fMRIprep experts,
I am using fMRIprep 1.5.1rc2 with synthetic fieldmap correction. In some subjects, it yielded very large/unrelistic FD, DVARS and GS etc. We checked the raw data and it does not contain such large fluctuations. I wonder if this has occured to anyone before and what the cause might be.
Thanks,
Oliver
Motion parameters (hence FD) are calculated before SDC, so that shouldn’t affect this. It looks like a severe motion correction failure in the last several volumes. Are there any artifacts in the data? You might try looking at it with MRIQC or some other quality control tool.