Estimating response function by using dwi2response msmt_5tt from single shell data

[dchristiaens]

Hi Koji,

@111

Is it possible to estimate white matter response function by using “dwi2response msmt_5tt” script from single shell data?
Or does “dwi2response msmt_5tt” only support multi shell data?

The msmt_5tt method estimates the average signal response in a WM-GM-CSF segmentation of a T1-weighted image. In and of itself, it will thus work in single-shell as well as multi-shell data. But as the warning highlights, the result (3 single-shell response functions) will not be very useful in resolving three tissues using MSMT-CSD, since it leaves you with an underdetermined problem: estimating 3 tissue volume fractions from only 2 b-values (b=0 and b=X).

@111

I have a dataset of some subjects having a multi-shell acquisition (b=0, 1000, 2000; 32 diffusion directions each b).
Im trying to compare the connectome of global tractography from multi-shell data with those from single shell data using multi-shell multi-tissue CSD algorithm.

Our implementation of Multi-Shell Multi-Tissue Global Tractography is not really designed for single-shell data. However, the question has come up a number of times and you can have a look at my earlier comments on the topic here. In summary, if you insist on working with single-shell (b=0 + b=X) data I recommend using a 2-tissue WM-CSF model within a white matter mask.

Hope this helps,

Daan