Re: [Freesurfer] transformation question

2019-07-29 Thread Greve, Douglas N.,Ph.D.
The registration matrix maps an XYZ coordinate in the diffusion space to an XYZ coord in the anatomical space. This appears to be counter intuitive. In the end, the direction is not very important because you can just invert the matrix to go the other way. It only really becomes important if yo

Re: [Freesurfer] transformation question

2019-07-23 Thread Sam W.
External Email - Use Caution Thanks Doug! Could you clarify what you mean by the registration already being in anat-to diffusion? The only thing I did was to run bbregister using B0 as the -mov image and saving the reg.lta. If I understood correctly the registration matrix should

Re: [Freesurfer] transformation question

2019-07-22 Thread Greve, Douglas N.,Ph.D.
Use lta_convert with --invert. BTW, the registration matrix is already anat-to-diffusion On 7/22/2019 7:50 PM, Sam W. wrote: External Email - Use Caution Thanks Doug! I'll use lta then, but which tool do you recommend I use for inverting the matrix in order to have a freesurfer-to-diff

Re: [Freesurfer] transformation question

2019-07-22 Thread Sam W.
External Email - Use Caution Thanks Doug! I'll use lta then, but which tool do you recommend I use for inverting the matrix in order to have a freesurfer-to-diffusion registration matrix? bbregister does not seem to offer the option to invert matrices. Is tkregister2 the preferable

Re: [Freesurfer] transformation question

2019-07-22 Thread Greve, Douglas N.,Ph.D.
In most of the tools there is an option to invert the matrix before you apply it. If you save the registration matrix as an LTA instead of DAT, then most of the tools will figure out the directionality. On 7/22/19 4:24 PM, Sam W. wrote: > > External Email - Use Caution > > Hi, > I would