hi,

if you are comfortable with python, you can do this very easily with nibabel and numpy. there is also a TSNR interface in the nipype package.

http://www.mit.edu/~satra/nipype-nightly/interfaces/generated/nipype.algorithms.misc.html#tsnr

cheers,

satra

On Wed, Jan 25, 2012 at 9:53 AM, Maartje Luijten <[log in to unmask]> wrote:
Dear All,

I would like to calculate voxel-wise signal to noise maps and temporal signal to noise maps (functions in signal to noise over time).
Does anyone knows how to do this (possible using imcalc or a script)?

I searched on the mailinglist archives and found the message below. Unfortunately, the message that is referred to is no longer available.

All suggestions are welcome.

Thanks a lot!
Maartje

Hi,

If you want a voxelwise mean over a voxelwise standard deviation for a
bunch of images, i.e. you want an SNR image, then use spm_imcalc_ui as
in this post:

http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0608&L=SPM&P=R45864  <http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0608&L=SPM&P=R45864>

If you want mean over std of the voxels of a single image, then the
attached should do the trick. And if you want something else, please
ask again!

Best,
Ged.


--
Maartje Luijten, MSc
Institute of Psychology
Erasmus University Rotterdam
Woudestein T13-07
PO Box 1738
3000 DR Rotterdam
The Netherlands
Tel: +31 10 408 9729
Mob: +31 647 949 807
Fax: +31 10 408 9009
E-mail: [log in to unmask]