Threshold for visualization in FBA analysis

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Hi Mrtrix Developers,

I have recently done FBA analysis and ran fixelcfestats on a group of 17 controls and 15 disease subjects. I dont know how to interpret the results of fixelcfestats. I followed the instructions given in mrtrix doc to visualize the p-values using tsf files. I am not sure about the threshold value to set for the p-value (min threshold value and max threshold value, is it 0 and 0.05 respectively). I have selected fwe pvalue.tsf as the ‘colour by (track) scalar file’ and the same as the ‘Separate Scalar file’ in the thresholds dropdown menu. The reason behind my doubt is I see p-values of zero everywhere throughout the whole brain tracks. I am unsure about selecting the significant fixels.

Please see the below screenshots ,

  1. whole brain tractogram 200000 tracks
  2. fwe_pvalue.tsf as colour by (track) scalar file ( See all the fixels in black colour which denotes p-value of around 0), Is it something wrong with my visualization or with the GLM analysis?
  3. Display zoomed in

Thanks for any suggestions.

Best,
Rajikha

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Hi there,
I think the issue is the thresholds you’re using for your tsf file (they should be min 0.95 and max 1 if you’re looking to visualise p-values < 0.05).
Hope this helps.
Cheers,
Remika

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Thank you Remika