http://onlinelibrary.wiley.com/doi/10.1002/hbm.23318/full

this paper pertains to a method (eddy_correct) that we have recommended against for the last three years. We believe that our current method does a quite good job at estimation movement in the presence of distortions, as can be seen for example in https://www.ncbi.nlm.nih.gov/pubmed/26549300 (which we didn’t write). You can also have a look at figure 7 in http://www.sciencedirect.com/science/article/pii/S1053811915009209 (which we did write).

As has been discussed earlier on the mailbase there is a particular “problem” with estimating translations in the PE-direction, so these should be treated with some caution. Our current recommendation for assessing overall movement is there for the .eddy_restricted_movement_rms. There are some explanation how to use it in the EDDY wiki pages.

Jesper

Did you acquire multiple Bval=0 scans in the course of each DTI? They'd be less distorted by eddy currents, so give you a handle on overall motion during the series.

On 22 September 2016 at 15:18, Thais Minett <[log in to unmask]> wrote:

Dear FSL experts,

I am submitting my DTI-TBSS analyses paper for publication. One of the reviewers asked me: "The authors should report on some metric describing the level of head motion in each group during the DTI scan.". I have no idea how I should address that. I used ‘eddy’ and not ‘eddy_correct’ for my data processing.

Regards,

Thais Minett

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Michael John Knight, PhD

Elizabeth Blackwell Institute Early Career Fellow

School of Experimental Psychology and School of Clinical Sciences

University of Bristol

Tel 07920 113060