Get unique fixel masks by subtraction of two masks

Hi all,

I’ve got two fixel-masks thathave some fixels in common. Now I want to create a mask containing only unique fixels (i.e., fixels that are part of one mask, but not the other).

For this, I’ve tried subtracting the two masks using "mrcalc mask1.mif mask2.mif -subtract mask-difference.mif, but I already figured out that that’s resulting in what I need. Any suggestions?

Thanks!

I’m not sure I’ve necessarily got exactly what you’re after, but if I understand correctly, you want all fixels in mask 1 that are not also in mask 2? If so, then this ought to do the trick:

mrcalc mask1.mif mask2.mif -not -and mask1-unique.mif
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Hi all,

I have a similar question…

I generated two different FBA pipelines in the same space, and in each pipeline a comparison is made between patients and controls. Ultimately, I want to investigate differences across pipelines.

I used the following command to create a fixel mask which show fixels that are significantly different between patients and controls in each pipeline

mrthreshold fwe_1mpvalue.mif -abs 0.95 fwe_1mpvalue_threshold0.95.mif.gz

The output for both pipelines are shown here in red and yellow.

I want to create a new set of masks that show:
(1) fixels that are significant to both pipelines (intersect of red and yellow)
(2) fixels that are significant in red, not yellow
(3) fixels that are significant in yellow, not red

Donald’s suggestion is probably going to help with this. However, the red and yellow masks have different dimensions…

I have also run
mrgrid red.mif -template yellow.mif regrid red_regridded.mif
to regrid red to match yellow, but I am unsure about the validity of red_regridded.mif

So, is there any way of answering (1-3) without using mrgrid? Or, how do I check that the regridded fixels are sensible?

Cheers,
Arkiev

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Hey everyone,
I’m also interested in comparing fixel masks across FBA pipelines, and have run into similar problems with subtracting masks due to differences in dimensions…just wondering if there are any solutions/suggestions on how this can be done?

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just for everyone else’s benefit, fixelcorrespondence can be used in here.