Dear John and SPM list,
Using the unified segmentation in SPM5 (with the more recent updates
installed), we noticed that for a large proportion of subjects (30%), voxels
belonging to the skull were misclassified into the CSF class (see example
below).
http://www.mediafire.com/?2dfm4jjxyjp
- Top left: normalized MRI.
- Top right: segmented CSF map using SPM2 optimized VBM.
- Bottom left: SPM5 segmented CSF map.
As a result, the CSF volume estimation for this subject is 705 cm3 instead
of 442 cm3 which seems more reasonable using the optimized VBM with SPM2.
Has anyone else noticed that and are there any ways to improve this result?
Thanks in advance for your suggestions,
Herve Lemaitre
_____
Herve Lemaitre PhD
Clinical Brain Disorders Branch, NIMH
Building 10, Room 3C-108
10 Center Drive, MSC 1384
Bethesda, MD 20892-1384
Phone: (301) 594 9922
Fax: (301) 451 4269
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