Hi Doug,
Why Qdec offer "volume, area, thickness ,...etc " in the drop down menu "measures"? In this menu there are many measures and I understand that I can run surface based analysis depending on the choice of this drop down menu. Is this Correct? Please see attached. Thank you for any clarification
I'm not sure I follow. If I understand, you are finding sig diff in PCG volume when you extract it the volume value for each subject (scaled by
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
greve@nmr.mgh.harvard.edu
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
���1�E�
