So if I wanted to derive some kind of measure of the complexity of cortical folding, would .curv be the way to go? Would it be safe to say regions of higher curvature have greater cortical folding?
Alex Fornito M.Psych/PhD (clin. neuro.) candidate Melbourne Neuropsychiatry Centre and Department of Psychology The University of Melbourne alexander.fornito@wh.org.au
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From: Bruce Fischl [mailto:fischl@nmr.mgh.harvard.edu] Sent: Tue 25/10/2005 10:57 PM To: Fornito, Alexander Cc: freesurfer@nmr.mgh.harvard.edu Subject: Re: [Freesurfer] .sulc and .curv
1. This is the smoothed mean curvature - the average of the two principal curvatures smoothed spatially.
2. sulc is the integrated dot product of the movement vector with the surface normal over the inflation process. Things that move consistently outwards thus get a positive sign (sulci) and inwards a negative sign (gyri).
3. curv highlights secondary and tertiary folds as much as primary ones, whereas sulc highlights the primary, deep folds.
Bruce
On Tue, 25 Oct 2005, Fornito, Alexander wrote:
Hi, I was just wanting to know more about the .curv and .sulc files. Specifically, I had three questions: 1 - What exactly does the value assigned to each vertex represent (eg., is it the curvature of the vertex in the .cuv file?) 2 - How are they derived/calculated? 3 - What do they mean neuroanatomically (eg., does .sulc correspond to the depth of a sulcus?). Many thanks, Alex
Alex Fornito M.Psych/PhD (clin. neuro.) candidate Melbourne Neuropsychiatry Centre and Department of Psychology The University of Melbourne alexander.fornito@wh.org.au
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