Hi John,
Thanks for your reply. I believe I am using the most recent version of
spm_preproc.m. Here is the version info from the file:
% $Id: spm_preproc.m 570 2006-07-05 14:29:24Z john $
A colleague of mine was using the earlier version and we both got
virtually identical results. The CSF in the lateral ventricles was
mostly misclassified as background in our MPRAGE image. The intensity
of CSF in this sequence is very similar to that of air, so I believe
this is part of the problem, however SPM2 does a fine job at segmenting
the CSF, while SPM5 is failing even with the most recent updates.
I could send you a snapshot of the segmentation result if that would
help.
Thanks in advance for any further insight you may be able to offer.
Best wishes,
-Matt.
On Wed, 2006-09-13 at 05:44, Ashburner John (PSYCHOLOGY) wrote:
> Ideally, the warping would be done in a more symmetric way (possibly by
> doing two half-way warps so that both are matched to their mean).
>
> There was no major reason for choosing to warp the late to the early
> image, rather than the other way around.
>
> Best regards,
> -John
>
> -----Original Message-----
> From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
> On Behalf Of Matthew L. Senjem
> Sent: Tuesday, September 12, 2006 11:11 PM
> To: [log in to unmask]
> Subject: Re: [SPM] longitudinal VBM/TBM
>
> Hello John and list,
>
> I have another quick question regarding the
> methods in the following paper:
>
> C M Kipps, A J Duggins, N Mahant, L Gomes, J Ashburner, and E A McCusker
> Progression of structural neuropathology in preclinical Huntington's
> disease: a tensor based morphometry study
>
> My question is, why did you choose to warp the "early" image to the
> "late" image, instead of vice-versa?
>
> The reason I ask this is because in a post to this list (which predates
> the article in question) you recommended warping the "late" image to the
> "early" one.
>
> Sorry for asking so many questions, and thanks for your time and
> patience.
>
> Best wishes,
> Matt.
--
Matthew L. Senjem
Analyst Programmer - Imaging Systems
Mayo Clinic and Foundation
Mail Code: RO_CE_09_IMAGING
200 First St. SW
Rochester, MN 55901
[log in to unmask]
Fax: 507-284-9778
Phone: 507-538-0764
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