Hi Bruce,
I drew ROIs on an initial subject and then after registering all other subjects to the initial one, used mri_label2label to map the ROIs from the initial subject to subsequent ones. I am interested in looking at asymmetry between left and right regions.
I had two concerns, one that the ROIs have different # vertices on different subjects, but as you mentioned the nonlinear process makes sense, since each subject does not have the exact same brain size and curvature.
Another concern was that the ROIs on the left and right hemisphere in a subject do not have the exact same number of vertices. Would a difference of 10 vertices max bias results?
Thank you for your help,
Daiana R. Pur Research Assistant Canadian Surgical Technologies & Advanced Robotics Brain and Mind Institute Western University London, ON, N6A 5B7 Canada
On Mon, Oct 24, 2016 at 12:09 PM, Bruce Fischl fischl@nmr.mgh.harvard.edu wrote:
Hi Daiana
yes, that is to be expected given the nonlinear nature of the cross-subject registration. It shouldn't bias things, although you'll need to give us more details if you want a more definitive answer.
cheers Bruce
On Mon, 24 Oct 2016, Daya P wrote:
Hi All,
My question is about using mri_label2label. When mapping the labels from one subject to another the number of vertices of each ROI is different. Is that something to be expected?
How much of a difference does a number of vertices of 50 compare to 40 have on measures like thickness, grey matter and surface area?
I would really appreciate some help
Thank you,
Daiana R. Pur Research Assistant Canadian Surgical Technologies & Advanced Robotics Brain and Mind Institute Western University London, ON, N6A 5B7 Canada
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