Hi
> So theoretically is it incorrect to rotate the bvecs from the 12 dof affine matrices used during eddy_correct?
yes
> Practically I don't see a difference, as has been mentioned by this group before.
true, but might make a difference if you have massive eddy-currents
Saad
>
> Dustin
> ________________________________________
> From: FSL - FMRIB's Software Library [[log in to unmask]] On Behalf Of Satrajit Ghosh [[log in to unmask]]
> Sent: Wednesday, February 01, 2012 1:36 PM
> To: [log in to unmask]
> Subject: Re: [FSL] utility of rotating bvecs [was: Re: [FSL] Rotate bvecs]
>
> so your question is: is it more robust to estimate a 6dof flirt or a 12dof flirt in order to get the actual rotation. my guess is 6dof is more robust (espcially at higher b), but if you are using eddy_correct to correct eddycurrents as well, then you should extract the rotation from the 12dof flirt.
>
> thanks.
>
> satra
>
--
Saad Jbabdi
University of Oxford, FMRIB Centre
JR Hospital, Headington, OX3 9DU, UK
(+44)1865-222466 (fax 717)
www.fmrib.ox.ac.uk/~saad
|