I think the right way to do it is to use the symmetric template (fsaverage_sym) as the target (instead of fsaverage). You will need to run the symmetric registration. See http://surfer.nmr.mgh.harvard.edu/fswiki/Xhemi (if you have 5.2, you do not need to download anything). You can map either the left hemi or right hemi to the template, depending upon the subject. I'm not sure you can use QDEC at that point, depending upon what you want to do. doug

On 3/12/13 3:22 AM, Kristina Nalbandian wrote:

Hello!

I am running qdec group analysis on my patient data and have one very important question. I am studying the differences between two Epilepsy subtypes. Each one of my patients has a hemisphere of onset, either Left or Right, that I would like to use in looking for differences between ipsilateral and contralateral hemispheres. However, ipsilateral patients need to be grouped together, but qdec only allows me to visualize left or right hemispheres separately. Is there a way to combine left hemispheres with right hemispheres in an attempt to study grey matter thickness in hemispheres ipsilateral to seizure onset? [Because the ipsilateral hemisphere is the right hemisphere for some patients and left hemisphere for others]. For example, is it possible to somehow flip the right hemisphere such that ipsilateral hemispheres align together?

Thank you in advance for your help, Kristina Nalbandian

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