Hello All,
I seem to have confused myself about left and right...so I need to touch base
with some experts.
Here's the scenario:
We collect a functional spiral file and T1 in radiological orientation.
However, we collect our high resolution spgrs in neurological orientation.
We use the default defaults.analyze.flip=1 for spm2 because the functional and
T1 are indeed radiological.
However, we L-R flip the spgr so that it will be in radiological orientation as
well....this flipping is, of course, recorded in the mat file.
Now, when spm2 displays any of our images, it will look at the
defaults.analyze.flip=1
and it will display everything in neurological orientation (flipped)...
BUT, doesn't spm2 also know that we have flipped the spgr L-R? If so, what are
it's assumptions in displaying that image?
Possibility 1) It displays the image correctly because it reads
defaults.analyze.flip=1....assumes the image is radiological (which it is now),
and flips the display into neurological. End of Story.
Possibility 2) It tries to be clever...assumes we started with the spgr in
radiological, that we flipped it into neurological and now it does NOT flip
again when it displays. (If this is the case, then we see the wrong thing
because it now displays the spgr in neurological orientation.
Thanks in advance for your insights,
Dianne
Dianne K. Patterson Ph.D.
Psychology, Room 217E
626-4571
Cognition and NeuroImaging Labs
University of Arizona
Tucson, AZ
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