HI - it depends on your confidence in the accuracy and objectivity of the
mask. You would probably get better results by taking the intersection of
FAST GM output with a general mask than trying to just mask the GM by hand
(I'm not sure which you were suggesting). Also, if you are using
standard-space masks, the accuracy depends on the non-affine subject
variability in this region.
Cheers, Steve.
On Wed, 24 Aug 2005, Matt Holloway wrote:
> Thanks for the reply. A more general question . . .
>
> Do you think it is feasible to measure the volume of a brain region that has been isolated with a
> mask? Is this too "rough" a method for isolating a region of interest given that grey matter volume
> is of interest (i.e. Would the correct path be to segment the ROI's in individual subject strucs by
> hand?)?
>
> Thanks again,
>
> Matt Holloway
> Research Technician
> Treatment Research Center
> Brain Imaging & Conditioned Factors Division
> 3900 Chestnut Street
> Philadelphia, PA 19104
> Phone: (215)222-3200 ext. 204
> Fax: 215-386-6770
>
>
--
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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