Hi
First, you need to work out the height of the waveform in your model. If
you have a block-design then it is most likely to simply be exactly 1
(look in design.mat). Let's say though for the sake of example that it is
actually 1.1
Then, for example
take an example time point from the filtered data (to use as baseline)
avwroi filtered_func_data egvol 50 1
find the percent image
avwmaths cope1 -mul 1.1 -mul 100 -div egvol percent_image
ttfn :)
On Thu, 7 Feb 2002, Antti Korvenoja wrote:
> Hi!
>
> I would like to get an estimate of the magnitude of the signal change for a
> given contrast (e.g percent change). How to derive such a measure from FEAT output?
>
> -Antti Korvenoja
>
> ----------------------------------------------------------------------------
> Antti Korvenoja
> Dept. of Radiology & BioMag Laboratory, Helsinki University Central Hospital
> Biomedicum Helsinki, P.O. Box 700, FIN-00029 HUS, Finland
> tel:+358-9-471 71786 * gsm:+358-40-7498469 * fax:+358-9-471 75781
> [log in to unmask] * http://www.helsinki.fi/~akorveno/
> ----------------------------------------------------------------------------
>
Stephen M. Smith
Head of Image Analysis, FMRIB
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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