[Neuroimaging] noise estimation in non diffusion datasets

[Samuel St-Jean]

Hello,

I've been trying out some stuff recently with another guy on 'legacy' 
datasets, which comprise CT scans and stuff like T1w which are 0.8x0.8x8 
mm. Unsurprisingly, they also have huge gradient intensity since these 
things dates back from when I started high school. Anyway, they also 
have diffusion data and noise estimation stuff works kind of ok, but the 
other weighting and modality are mostly a no go or perhaps could be done 
way better) using the diffusion tools we have now.

So far I've also tried an aonlm-like noise estimator, but I was 
wondering if people working with all types of datasets (I am mostly a 
diffusion mri person in the first place) had suggestions about good or 
commonly used noise estimator and where to find them? Most likely 
candidate for that would be the fmri guys I'd guess, and of course those 
scans did not have a/some noise maps back in the days.

Thanks for the help and pointers,

Samuel