Hi,
For FMRI the most relevant ratio is the CNR (contrast to noise), i.e.
activation strength divided by noise. This is exactly what the tstat
(and equivalently the zstat) gives you, so you can just use the FEAT-
derived zstat images for the comparison.
Cheers.
On 11 Feb 2009, at 18:38, Zarrar Shehzad wrote:
> Hi
>
> I am trying to compare the SNR of a finger tapping task between
> different pulse sequences. I understand that one method is to take the
> mean-int/sd(noise). Is there a way to use output generated from feat
> to calculate SNR, for instance using t statistic and sigmasquareds
> images?
>
> Thanks
> Zarrar
>
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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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