MRTrix dwibiascorrect error

1

Here’s the pertinent error message and something I want to share with the MRTrix community with the hope of getting feedback.

dwibiascorrect: [ERROR] dwiextract in.mif - -bzero | mrmath - mean mean_bzero.mif -axis 3 (fsl.py:58)

This looks to be caused by the fact that our bvals have non-zero b-values for the lowest shell (bval=62)

The error goes away when we manually edit b-value=62 to 0.

Is there an additional flag or options we can specify to circumvent this other than manually editing the bval table (e.g. specify bval shell for dwiextract routine inside dwibiascorrect)?

2

Hi,
It seems it happens because mrtrix3 default option for BValueEpsilon which is 80, so it puts your b=62 and b=0 in the same shell. To avoid that you can change the value for BValueEpsilon to 20 (for example) by adding the line BValueEpsilon: 20.0 to your ./mrtrix.conf file.