> Thanks for your response. Our cleaned up GM/WM look great, but the final
> product looks very blurred and wrong. After cleaning up the GM/WM we
> 'determined parameters and wrote normalized' the cleaned up gray image to
> our gray template and then 'wrote normalized' our original image with
> those parameters. After segmenting this normalized image, the segments
> look very odd. There is gray matter outside the brain and in the
> ventricles too. What could be going wrong?
Has the normalisation worked? Use the Check Reg button to ensure that
this is OK. In order to segment an image, SPM overlays a set of prior
probability images of different tissue classes. Try checking that these
are in reasonable register with the spatially normalised image.
Also, it is better if the images are written spatially normalised to a higher
resolution (1 or 1.5mm voxels - specified via the Defaults button).
Best regards,
-John
--
Dr John Ashburner.
Functional Imaging Lab., 12 Queen Square, London WC1N 3BG, UK.
tel: +44 (0)20 78337491 or +44 (0)20 78373611 x4381
fax: +44 (0)20 78131420 http://www.fil.ion.ucl.ac.uk/~john
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