help > Discrepancy in results by MRIcron: NPM and VLSM Toolbox
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Apr 30, 2022  07:04 AM | Sachin Patalasingh - NIMHANS
Discrepancy in results by MRIcron: NPM and VLSM Toolbox
Hello VLSM experts,

I am trying to run VLSM on some glioma patients (N=85). I am using both MRICron NPM and VLSM Toolbox by Stephen M. Wilson. However I am shocked to see different results in both. I am using 8000 permutations in both the process still the regions coming in the results are very contradictory to each other.
So, I was wondering if I am doing any mistakes or is there any problem in the software itself?
I would appreciate any kind of help on this. Thank you in advance.
Best,
Sachin
May 24, 2022  01:05 PM | Chris Rorden
RE: Discrepancy in results by MRIcron: NPM and VLSM Toolbox
First of all, are you using a GLM-based statistic (e.g. t-test) or the non-parametric Brunner-Munzel test? There are differences in the fundamental assumptions of NPM and VLSM. Each is a valid way of testing for differences based on these assumptions. While I am happy that NPM has proved robust and popular, I no longer maintain it. You may want to try my NiiStat. Alternatively, I am a huge advocate for Anderson Winkler's PALM. I only created NPM/NiiStat because PALM did not exist at that time.