I plan to use FD thresholds to identify outliers in functional runs, and
to eliminate runs entirely when there are too many frames above a given
While comparing the FD calculations in an MRIQC individual report to those
reported in the fmriprep confound file, we get differing results, but
not in a systematic way. The two FD calculations are related, but the
fmriprep FD value for a frame will be slightly higher and other times
slightly lower than MRIQC’s FD value.
(Comparisons were made between FD column in the fmriprep confounds file and the FD
vector that is plotted in the MRIQC report, with values found in the
fd_power_2012.txt file inside the MRIQC working directory).
Does anyone know why this occurs? Is this a bug in one program or the other? Is one report more accurate?