Dear FSL users, Doug,
mri_segstats gives a table of functional activations calculated by FSL
and masked by cortical and subcortical segmentations calculated by
freesurfer. i am wondering if there is a way of converting the results
of the mri_segstats to "%signal change".
here is what i did:
step_1)
as described under "3.0 Creating ROI summaries"
(https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/MapSegmentationsToFunctionalSpace)
i used "mri_segstats --seg aparc+aseg.nii.gz --nonempty --ctab-default
--in subject/stats/cope1.nii.gz --sum cope1.sum.txt" to make a table of
mean/min/max activations for each segmented area.
step_2) then i fed filtered_func_data to mri_segstats to find the mean
intensity over time for each segmented area:
mri_segstats --seg aparc+aseg.nii.gz --nonempty --ctab-default --in
filtered_func_data.nii.gz --sum mean.sum.txt
step_3) then i tried to normalize the mean activations i found in step_1
by the mean intensities found in step_2 to get the "% signal change".
to double check the results, i used featquery to calculate the " %
signal change" for two segmented areas.
here is the problem:
the results i get from step_3 are NOT close to the "%signal change"
results that featquery creates for the two areas i checked (hippocampus
and amygdala).
i am wondering if you can give me some insights on how to calculate the
"%signal change" correctly via mri_segstats.
thanks
paymon
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