I think some of the greatest benefits and easiest changes to help your
experiment involve adjusting your MR scanning parameters. You can ask your MR
physicist to come up with a better protocol, possibly at the expense of a
longer scanning time. If you google for "freesurfer", which is a
commonly used
cortical surface package, you may be able to get some ideas of good scanning
parameters, because the use of this package depends a great deal on the
gray-white contrast of your scans.
But, before you go scanning a lot of subjects, Id advise you to take a look at
the Washington University dataset at fMRIDC. The fMRIDC will mail you DVD
copies of any dataset they have (for free!!!), and there is one dataset in
particular comprising over 150 subjects, acquired in high-resolution with good
gray-white contrast, that contain groups of patients with normal aging and
Alzheimers.
Take a look:
http://www.fmridc.org/f/fmridc/database/specialcollections.html
good luck,
ken
Quoting Flavio Seixas <[log in to unmask]>:
> I'm Flavio, master of science stundent at Universidade Federal
> Fluminense, Brazil. I'm working with neuroimaging segmentation. The
> objective is get temporal mesial structures shapping and analyse
> their corelation to Alzheimer disease.
>
> I haven't get the segmentation using SPM. The MRI images seems to be
> grainy with low contrast. Is there any denoising algorithm that could
> I try to improve the SNR ratio?
>
> Thank you,
> Flávio.
>
>
> ---------------------------------
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----------------------------------------------------
Ken Roberts
Woldorff Laboratory
Center for Cognitive Neuroscience, Duke University
(919) 668-1334
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