[Mristudio-users] Late Stage AIR?

[Dylan Alegria]

Hi,
I'm still a novice with DTIStudio, and I've run into a concerning  
issue during fiber-tracking.  We collected a 30 direction DTI sequence  
with 2 repetitions on 25 subjects and have run it through DTI Studio  
to do fiber tracking.  We did not initially register with AIR because  
we believed that our subjects were reasonably aligned and we didn't  
want to add artifacts from registration if we didn't have to.

While drawing ROIs for fiber tracking some differences in tilting are  
obvious.  We are considering running AIR on the processed data to  
remedy this problem.  This brings me to 3 questions.

1) Given that fiber tracking operates in a 3D space, how important is  
it to have subjects in exactly the same alignment for drawing the seed  
ROIs?
2) Is it possible to register the FA/Eigenvector/etc. images without  
recalculating them, or going back and re-flagging bad slices?
3) Is it of vital importance to run AIR before doing the quality  
checks for some other reason than having similarly aligned subjects?

Any help would be greatly appreciated.  Thank you very much in advance!

Dylan


Dylan Alegria
CIBSR Imaging RA
Stanford University
dalegria at stanford.edu
(650) 736 0732