I am sorry if my question was not clear enough!

In Qdec/ tab "design" the user have the choice to choose the analyses that he wants to conduct on aseg,mgz, wmparc.mgz or aparc+aseg.mgz.

These atlases report white and gray matter volumes.

in Qdec, if I choose volume from the dropdown menu "measure" under the tab "design" to conduct surface based analyses. Dose this means surface based analyses for gray matter volume or white matter volume?

In aseg you can find both volumes for whit matter and gray matter. so which volume is Qdec referring to? If Qdec compute surface based analysis of gray matter volume, then how can I do surface based analysis using the whiate matter volume of the parcellates instead of the gray matter voluem of the parcellaets? Is this feasible

-------- Original Message --------

Subject: RE: [Freesurfer] White matter atrophy

Local Time: April 20, 2017 10:04 AM

UTC Time: April 20, 2017 2:04 PM

From: AYENDIKI@mgh.harvard.edu

To: John Anderson <John.anderso@protonmail.com>, Freesurfer support list <freesurfer@nmr.mgh.harvard.edu>

Hi John - Unless someone else has a better idea, the aseg (subcortical segmentation) contains left and right cerebral and cerebellar white matter labels. You can look at the ROI analysis tutorial for how to extract stats from aseg labels.

Best,

a.y

From: freesurfer-bounces@nmr.mgh.harvard.edu [freesurfer-bounces@nmr.mgh.harvard.edu] on behalf of John Anderson [John.anderso@protonmail.com]
Sent: Thursday, April 20, 2017 7:42 AM
To: freesurfer@nmr.mgh.harvard.edu
Subject: [Freesurfer] White matter atrophy

Dear Freesurfer experts,

I know how to do cortical thickness group analysis using Freesurfer, also I know how to use Qdec to compare groups regarding gray matter volume differences, cortical thickness, curvatures, area,... etc.

I am wondering if there is any way in Freesurfer to study the difference in white matter volume between two groups?

I highly appreciate any suggestion!

John

The information in this e-mail is intended only for the person to whom it is

addressed. If you believe this e-mail was sent to you in error and the e-mail

contains patient information, please contact the Partners Compliance HelpLine at

http://www.partners.org/complianceline . If the e-mail was sent to you in error

but does not contain patient information, please contact the sender and properly

dispose of the e-mail.