I think it depends on how badly deformed your DTI maps are. I sometimes need to use 12 DOF but I would check the coregistration manually to make sure that you have a good match between the B0 magnitude map that goes with your field map and the DTI maps. DTI maps are notorious for having spatial deformations which cause problems for coregistration even for the S0 map or non-diffusion weighted map.
-----Original Message-----
From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf Of Forrest Johnson
Sent: Thursday, June 17, 2010 7:41 AM
To: [log in to unmask]
Subject: [FSL] Fugue Registration 7 DOF
Hello Experts,
I am running a gradient field map correction on my DTI data and was wondering about the registration set up. The Fugue practical states to use 7 DOF for the structural image and I was curious as to why I need to use 7 DOF rather than 6 DOF.
Cheers
|