John Ashburner wrote:
> Look at the intensity within the white matter, and compare the values at the
> top of the brain with those in e.g. the cerebellum. The cerebellum WM is
> darker in the uncorrected images. After correction, the cerebellum is then
> as bright as the rest of the WM.
That's true, I hadn't looked carefully at the cerebellum. Good point.
> Because the images are scaled according to the maximum value
> in the volume,
Hang on, is that actually desired? Are you saying that if one image
has a bright flow-artefact then its GM/WM intensities will be scaled
down? Doesn't one generally want the bias correction to give similar
GM/WM intensities across the set of images?
I know this is what I want here, but I guessing that SPM doesn't mind
what the GM/WM intensities are among images, as long as they are
uniform within images, right?
Thanks,
Ged.
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