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Hi,
I want to compare mean curvature between groups on QDEC using the “curv”
measure. I've learned from the archives that FreeSurfer calculates numerous
curvature-based functions by default in the recon stream and stores them in
the “surf” directory. I have 3 questions that I would appreciate your
advice on:
1. I’ve already ran recon-all on all my subjects. Then, I also ran the
below command line for qcache. The "-measure lgi" is in my command line
because I am also planning to look at lGI differences between groups and
this is the qcache command line I use for the lGI measure. Now I'm asking
if this command line is appropriate for me to proceed with comparing mean
curvature between groups as well? or should I run a different qcache
command line before starting statistical analyses on mean curvature?
recon-all -s PC03_01 -qcache -measure pial_lgi
2. I don't smooth the lGI measure as the computation of this measure makes
it a relatively smooth construct. However, for mean curvature: what level
of smoothing do you recommend (i.e. 10 FWHM)?
3. I control for surface area when comparing lGI values between groups.
However, for mean curvature group comparisons, should I be controlling for
intracranial volume (ICV) instead?
I'd really appreciate your advice,
Thank you so much,
Avi