24 Jul
2018
24 Jul
'18
12:35 p.m.
For noise compare the values in the rstd.mgh file, for effect size look in the gamma.mgh file
On 07/24/2018 12:27 PM, Martin Juneja wrote:
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Hi Dr. Greve,
Thanks for your quick reply. Could you please give me more details how can I check this whether its because of noise or its because of less CV difference? I am not sure what method/way is the best and commonly used to confirm these factors.
Thanks.
On Tue, Jul 24, 2018 at 7:06 AM, Douglas Greve <dgreve@mgh.harvard.edu mailto:dgreve@mgh.harvard.edu> wrote:
your results could have vanished after ICV correction for one of two reasons: the CV difference became less or the values became noisier (or a combination). So check in your data which one of those things happened. On 7/23/18 8:30 PM, Martin Juneja wrote:External Email - Use Caution Hello experts, I am interested in identifying regions of interest by comparing cortical volume (CV) between controls and patients. After including age and sex as my covariates, I identified regions X1 and X2, which showed significantly lower CV for patients (as compared to controls). But after I include ICV as another covariate, my results show that for none of the areas there is any significant difference in CV, i.e. my results vanish. When I checked subjectwise ICV for each group, I found that there is almost significant difference (two-sampled t-test, p = 0.067) in ICV between two groups, but interestingly mean group ICV for patients group was larger compared than mean ICV for controls. But as I said earlier, regions X1 and X2 had significantly lower CV for patients (as compared to controls), when I didn't include ICV as covariate. Could you please help me in interpreting these results? Is there any advice regarding inclusion of ICV as covariate? Or my results are purely because of differences in ICV between groups, and there is no real findings regarding the regions identified (X1 and X2)? Thanks a lot ! _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer <https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer>_______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer <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 <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.
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