I would start by concentrating on a single pair of images that are
giving a surprisingly large SIENA result; run with the -d debug option
and look carefully at each stage of the outputs to see if you can
track down where things are going awry.
Cheers, Steve.
On 11 Jan 2009, at 16:52, Daniel Reich wrote:
> I'm looking for tips on using SIENA and SIENAX with MPRAGE data.
>
> Our data are 1.1 mm isotropic MPRAGE, collected on a 3T scanner. You
> can see
> results for a 31-year-old healthy woman at:
>
> ftp://ms-mri.marburg1.jhmi.edu/pub/10005_sienax.pdf
>
> Scans 1 and 2 are separated by about 6 months; scans 1 and 3 by
> about 2
> years. My impression is that the program is having problems finding
> the
> brain/CSF distinction accurately and reliably. Certainly, a 24%
> change in
> brain volume over 6 months in a healthy person is not desirable, but
> I get
> results like this frequently. Perhaps I'm doing something wrong.
>
> Thanks in advance for the help.
>
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR 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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