Hi Arnaud Have a look at the FAQ section of the EDDY documentation. There are some instructions on how to rotate the bvecs. Cheers Saad On 6 Aug 2014, at 19:40, Arnaud Boré <[log in to unmask]<mailto:[log in to unmask]>> wrote: Dear FSL experts, If I understand correctly when using eddy, there is a motion correction as well as eddy correction and geometric distortion correction. I would like to correct my gradient table using the output of eddy the eddy_parameters output file. There are 16 rows. Which rows should I use to correct my gradient table and how should I proceed ? Thank in advance for your help Arnaud ------------------------------------------------------------------ Saad Jbabdi, PhD MRC Career Development Fellow & University Research Lecturer FMRIB Centre, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK. tel (+44)1865-222466 (fax 717) www.ndcn.ox.ac.uk/team/researchers/saad-jbabdi<http://www.ndcn.ox.ac.uk/team/researchers/saad-jbabdi>