Dear List,
one of the possible preprocessing steps (as suggested by the list) for
tensor-based morphometry of gray matter is the calculation of a so
called "soft-mean" image for each subject. This "soft-mean" image (i3)
can be calculated by:
i3 = (i1+i2)./(eps + (i1~=0) + (i2~=0))
where i1 is gray matter segmentation of acquisition 1 and i2 is gray
matter segmentation of acquisition 2. this "soft-mean" gray matter image
(i3) can then be used as follows:
i4 = i3 * (Jacobian image -1)
the question: what is the purpose of this "soft-mean" gray matter image?
is it to maintain information on the probability of a voxel belonging
to gray matter?
thanks,
joost
Veronica
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