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Hi Marco,

Randomise can be used, but the number of possible permutations would be too small: just 15. However, if the errors are guaranteed to be symmetrical, it's possible to also do sign-flipping. We have an experimental tool that can do it, please, have a look at PALM: https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/PALM

All the best,

Anderson


On 13 May 2015 at 22:28, Marco Loggia <[log in to unmask]> wrote:
Hi all,

I have a PET image from a patient, and would like to compare it voxel-wise to a group of healthy controls (let's say N=15) to see if the patient is an 'outlier' in any voxels.

Ideally, for each voxel, I would perform the nonparametric-equivalent of a one-sample t-test, with the patients' value at that voxel as the reference value against which all the controls values are tested. From what I read, randomize wouldn't seem to do this, but I wonder if I could somehow implement a strategy similar to that used by the outlier detection algorithm.

Thanks!
Marco