 |
 |
Dear all,
I am facing a problem in the pre-processing of my fMRI data
and wonder if someone has already had this problem and could provide me with
some clues as to what the issue might be. Essentially, after the normalisation
of my data, I noticed that for some subjects the wu images were distorted with
quite a steep angle as seen on the sagital view. On the attached document, the
first two scan are from two different subjects for whom I get what I would
expect, but the other 5 scans have a much steeper angle despite being
accurately registered to the EPI template.
Initially I had another 4 subjects for whom the angle and
the registration was not great, but after setting the origin on the structural
scan to the ac-pc line and co-registering the EPI to the structural scan, it
solved the problem and these are now fine. For the other 5 subjects, however, this
did not solve the issue. My main concern is that these 5 subjects will
influence the final mask for the analyses and lead to a significant reduction
in the portion of the brain that will be covered.
In any light on this would be greatly appreciated. Thanks in
advance.
Best,
Steph’
-------------------------------------------------------------------
Stephane De Brito, PhD
Postdoctoral Research Associate
Developmental Risk & Resilience Unit
Division of Psychology and Language
Sciences
Tel: +44(0)20 7679 5394 (internal: 25394)
http://www.ucl.ac.uk/clinical-psychology/Research-Groups/DVR/index.htm