Dear SPM Mailing List,
In the documentation fo New Segment, it is suggested that determining the optimal bias regularization parameters should be a matter of empirical exploration. Is there a set of examples of different levels of spatially varying artifact? I can tell that there are differences across subjects in the intensity variations in both an MPRAGE and a T2 structural image (acquired coplanar to the EPI), but I would very much like to see some example images for which one would suggest different amounts of bias regularization.
Also, if I use both the MPRAGE and the T2 coplanar image (because the voxels are 1.5m x 1.5mm x 4mm, I first resliced the original coplanar image to the MPRAGE so as to be able to use both channels), is it possible to utilize a set of T2 tissue priors as well as those used for T1 images (are the TPMs that New Segment uses by default optimized for / only for T1 images)?
I have tried to use only the T2 coplanar images, or used the T2 and T1 images simultaneously but with the T2 in the first channel, but these segmentations always look as if the original intensities have been somehow inverted.
Thank you most kindly for your time and consideration!
~Will
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William E Moore III, M.S.
Developmental Social Neuroscience Laboratory
University of Oregon
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