Dwi2response for multi-shell data

[ThijsDhollander]

Hi @vanlam2308,

@vanlam2308

I have a multi-shell DWI data scan with 3 b-values including 0, 3000 and 6000. Can I go ahead using dwi2response dhollander to estimate response functions?

Yep, 100% fine! That’s the very purpose of this algorithm even.

@vanlam2308

Or should I need to extract them to single shell using dwi2extract and run dwi2response on every shells, then concatenate them at the end?

Nope! That would actually be wrong in certain ways; you’d get a multi-shell response in the end that’s a combination of single-shell responses from different sources (voxels in this case), something you definitely don’t want to have for various reasons.

dwi2response dhollander was designed for any number of b-values. The new 2019 version (which you’re probably not using here yet) even improves the single-fibre WM response estimation in particular for multiple b-values. (sources: ISMRM abstract and ISMRM talk)

If you’d like me to have a look just to be sure, happily post the contents of your estimated WM, GM and CSF response functions here. You can also get an image of the final voxel selection via the -voxels option. Here’s an old post on how you can visualise these voxels easily for inspection.

All the best,
Thijs