# Creating fixel mask for fixelcfestats

**URL:** https://community.mrtrix.org/t/creating-fixel-mask-for-fixelcfestats/5850
**Category:** Uncategorized
**Created:** [June 30, 2022, 2:35am UTC](https://community.mrtrix.org/t/creating-fixel-mask-for-fixelcfestats/5850 "2022-06-30T02:35:50Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![MrRibbits](https://community.mrtrix.org/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@MrRibbits](https://community.mrtrix.org/u/MrRibbits)
#### Post date: [June 30, 2022, 2:35am UTC](https://community.mrtrix.org/t/creating-fixel-mask-for-fixelcfestats/5850/1 "2022-06-30T02:35:50Z")

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Hi experts

After performing my FBA and looking at my null\_contributions.mif, I see that I have fixels \>10 in value.

I read [a post](https://community.mrtrix.org/t/how-to-improve-the-fba-results/4453/5) that said I should constrain my stats to a fixel mask containing fixels that have adequate streamline-based connectivity, and for now this can be done based on streamline count (until @rsmith makes it possible to do this based on the extent of fixel-fixel connectivity in 3.1.0).

Can someone help me with the commands I need to generate this fixel mask? And what’s a reasonable streamline count to use?

Would the commands be something like this?

tck2fixel tracks\_2\_million\_sift.tck fixels/fixel\_mask tck2fixel-output tck2fixel-output.mif

mrthreshold -abs 100 tck2fixel-output/tck2fixel-output.mif tck2fixel-output/tck2fixel-output-thr100.mif

Thanks ahead!  
Mark