I would say the biggest potential effect of TR would be on the amount of
vibrations there were in the scanner and the effects that can have on the
diffusion data. Otherwise, TR doesn't play a major role in diffusion
results (aside from affecting how many slices you can acquire) because of
the long time required for diffusion encoding. Different resolution, number
of directions, bvalue, TE, partial fourier, GRAPPA, etc, are more important.
Peace,
Matt.
-----Original Message-----
From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf
Of Jenifer Juranek
Sent: Wednesday, October 05, 2011 5:16 PM
To: [log in to unmask]
Subject: [FSL] Different TRs in DTI acqusitions
I've been looking at some DTI data for one of my colleagues. It appears as
though different TRs were used (e.g. 6125, 6500, 7100, 8374) across
subjects. Is this a huge problem for my colleague? What are the effects of
different TRs on DTI metrics like FA and MD? While I wasn't expecting such
differences in TR in my colleague's study, it's true that the published
literature has everyone's favorite TR for their own study. So the same issue
applies when evaluating results across studies.
Any thoughts?
Jenifer
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