Hi.
Before I answer your latest queries, I should correct a slight error in my
answer from yesterday - thanks to Christian for pointing this out:
when you do
avwstats structural_brain_pve_0 -V -M
353422 706844.000000 0.389197
you of course want to multiply the second number (not the first as I said
before) by the third in order to end up with total volume.
> I used avwstats to add up the lesion volume, like
>
> %avwstats s8_brain_pve_0 -R -V -M
> 0.000000 0.999992 156251 411989.941406 0.370034
>
> %avwstats s7_brain_pve_0 -R -V -M
> 0.000000 0.999997 151836 400348.828125 0.414307
>
> It looks like that it gives a volume include all intensity from 0 to 0.999.
> Can I give a lowthreshold and upthreshold to limit the intensity (like
> >0.5), though I don't know if it is necessery.
no - you don't need to use thresholds - as you are using -V which excludes
0 voxels, and are adding up partial volume values (0->1) you can use the
complete range.
you will be able to get the same results from MEDx, but you have to know
what their terminology means for the different statistics. If you get
stuck, email again and I'll have a play to see exactly what you need.
> My purpose is to compare the accuracy between MEDx and FSL for our study.
> I couldn't understand why they are so different between two method.
> Am I missing somewhere?
the real question about accuracy is wrt to the production of the partial
volume maps in the first place - the actual stats measurements will give
virtually the same answers between avwstats and MEDx - we've tested this
before.
Thanks, Steve.
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