Hi Doug,
etiv) and process in SPSS. The part I don't understand is
what you are doing with QDEC. I don't think QDEC can be used to test ROI
volume.
On 05/09/2017 05:58 PM, John Anderson wrote:
> Dear Dr Doug,
> I have two groups of subjects (80 patients and 40 controls).
I
> analyzed the data using Freesurfer v6.0.
> I want to study the difference between the groups in
"precentral gyrus
> volume". After "recon-all" I built
Qdec table and I used Qdec to
> compute the comparison by including eTIV a
covariate. After correcting
> the results using Monte Carlo simulation or
adjusting for FDR I found
> no difference between the groups in volume neither
in surface area.
>
> I adjusted the precentral gyrus volume values for
eTIV using the commands:
>
> mri_label_volume -eTIV
$SUBJECTS_DIR/${i}/mri/transforms/talairach.xfm
> 1948 $SUBJECTS_DIR/${i}/mri/wmparc.mgz 2017
mri_label_volume -eTIV
> $SUBJECTS_DIR/${i}/mri/transforms/talairach.xfm
> 1948 $SUBJECTS_DIR/${i}/mri/wmparc.mgz 2024
>
> I extracted the adjusted volume values to SPSS then
I ran box plots
> comparison between the groups and I found difference
at (P<0.0001) Why
> Qdec doesn't show the difference between the groups
although the p
> value is very small. What I am doing wrong in Qdec?
Is it wrong to
> include eTIV a covariate?
>
> Thank you for any advice
> John
>
>
> _______________________________________________
> Freesurfer mailing list
> Freesurfer@nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
--
Douglas N. Greve, Ph.D.
MGH-NMR Center
Phone Number: 617-724-2358
Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2
www.nmr.mgh.harvard.edu/facility/filedrop/index.html
Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer