In general you should use a registration file when viewing your results. In many cases, it may look like it is in registration with out a registration file. This can happen if you acquired your anatomical and DTI data in the same session. For this subject, were they acquired in different sessions or was the subject removed and replaced back in the scanner? When you sample the data onto the surfaces, you should always use a registration file.
doug
On 02/27/2014 05:08 PM, Celine Louapre wrote:
Hi Anastasia and freesurfer experts I am having some troubles with the registration of DTI images processed with tracula for one subject. When I load the lowb.nii.gz on freeview together with brainmask, it is not registered, but when I am loading it with the registration matrix anatorig2diff.bbr.dat, it is correctly registered. I don't have to specify the registration file for the other subjects, is that an issue of this particular subject? I am concerned because we later sampled surfaces on the DTI images, so I guess if the surf from the recon space is not correctly displayed on the DTI images, then my sampling is probably wrong too? The tracts are correctly displayed on the native DTI images, but if I want to display them on the anat space then it is not correct. Thanks for your help Celine