> I used the SVC option in previous studies to assess the number of voxels
> activated in a condition at a given threshold using a self-made mask
> (MRICRO). The script was a little altered by colleagues of KU Leuven in
> that way that the number of activated voxels in the ROI was displayed in
> the Matlab window. This has worked perfectly. However now I am conducting a
> study on single subject basis and I don't want to normalize my images. I
> made templates (ROI's) with mricro and did a check reg of this image with
> my functional images. They are in the same orientation. However when I want
> to run the (modified) SVC option to know how many voxels are activated in
> the ROI, SPM gives the following error: Mask image rotated/sheared!
> (relative to SPMimage) Can't use for SVC. Is this because I'm using
> non-normalized images and templates?? The mask images are made of a
> coregistered anatomy image, so they should be in the same orientation...
Some parts of SPM need the images to be aligned voxel for voxel, which can be
achieved using the <Coregister> button, and reslicing the mask image. The
resliced image may then need to be thresholded because it will contain a slightly
larger volume of non-zero value voxels (<ImCalc> with a threshold of ~ 0.5).
Best regards,
-John
--
Dr John Ashburner.
Functional Imaging Lab., 12 Queen Square, London WC1N 3BG, UK.
tel: +44 (0)20 78337491 or +44 (0)20 78373611 x4381
fax: +44 (0)20 78131420 http://www.fil.ion.ucl.ac.uk/~john
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