I'm sorry.

I'm performing the cortical thickness analysis on three groups (2 pathological groups and 1 control group). 

I'm interested mainly to the differences between the two groups of disease.

These are my questions:

1- Is qdec a good option for my study design or I should use other glm option that contains all 3 groups in the same matrix design?

2-As you suggest I'm using always mean cortical thickness as nuisance factor in qdec.

If I'd like added 2 or more covariates, is correct if I add each covariate separately in my matrix.dat or I should add all covariates together in my matrix.dat?

Thanks,


Stefano


----Messaggio originale----
Da: mharms@conte.wustl.edu
Data: 4-apr-2013 18.23
A: <stdp82@virgilio.it>, <freesurfer@nmr.mgh.harvard.edu>
Ogg: Re: [Freesurfer] R: Re: cortical thickness normalization


Hi,
Sorry, but I don't understand what you're asking.

-MH

-- 
Michael Harms, Ph.D.
-----------------------------------------------------------
Conte Center for the Neuroscience of Mental Disorders
Washington University School of Medicine
Department of Psychiatry, Box 8134
660 South Euclid Ave. Tel: 314-747-6173
St. Louis, MO  63110 Email: mharms@wustl.edu

From: <stdp82@virgilio.it>
Reply-To: <stdp82@virgilio.it>
Date: Thursday, April 4, 2013 9:31 AM
To: <freesurfer@nmr.mgh.harvard.edu>
Subject: [Freesurfer] R: Re: cortical thickness normalization

Thank you very much, Michael!

I have just an other important question, please.

I'm performing cortical thickness analysis on three groups. One of this is a control group and I'm using it as support because I'm interested only to difference between the two groups of disease.

These are my questions:

1- Is correct if I'm applying qdec, testing before a) disease 1 vs disease 2; b) controls vs disease 1 and c) controls vs disease 2.

2- Addictionally to cortical thickness that I'm reporting always as nuisance factor in qdec,  I'd test some covariates. 

Taking in account my study design, could I test each covariates separately on my model using qdec?

Thanks,


Stefano

----Messaggio originale----
Da: mharms@conte.wustl.edu
Data: 4-apr-2013 15.45
A: <stdp82@virgilio.it>, <freesurfer@nmr.mgh.harvard.edu>
Ogg: Re: [Freesurfer] cortical thickness normalization

If you're studying thickness, I'm a fan of using mean cortical thickness as the covariate (since thickness is what you're studying).  I've posted on this in the past.

cheers,
-MH

-- 
Michael Harms, Ph.D.
-----------------------------------------------------------
Conte Center for the Neuroscience of Mental Disorders
Washington University School of Medicine
Department of Psychiatry, Box 8134
660 South Euclid Ave. Tel: 314-747-6173
St. Louis, MO  63110 Email: mharms@wustl.edu

From: <stdp82@virgilio.it>
Reply-To: <stdp82@virgilio.it>
Date: Thursday, April 4, 2013 7:21 AM
To: <freesurfer@nmr.mgh.harvard.edu>
Subject: [Freesurfer] cortical thickness normalization

Hi list,

I'm reading a lot of post on this list about cortical thickness normalization. 

I' m noting very different results on my data when I use mean thickness or ICV as nuisance factor than no factor. 

I'm confuse on this topic, could you advise the best way, please? 

Thanks,


Stefano
_______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.eduhttps://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer 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.

_______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer 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.