Hi,
I am new to SPM and am still trying to explore all of its capabilities. I
have just begun a project to try to find total volumes (over the whole
brain) of gray matter, white matter, and CSF, using T1 MRI Head studies.
Using the three output images (one for GM, one for WM, and one for CSF),
could someone please explain the procedure to calculate whole volumes of
each image.
I understand that the segment images will return an intensity value for the
specified voxel that is clicked on or specified by 3D coordinates, and that
the intensity is the probability of that particular voxel being gray or
white or CSF, depending on which image I am looking at. My question is, is
it possible to convert from those probabilities into a volume in cubic
millimeters, and then is there a way to sum them over the entire image? and
is it possible to set a threshold value to limit the probability values?
And if all of that can be done, how might I then specify the sum over
certain regions of the brain such as the hippocampus to find out, for
example, the volume of gray matter in the hippocampus as seen in that
particular study?
any information would be much appreciated.
-Matt Wagner
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