[Mristudio-users] effect of TE on FA

[Dorian Pustina]

Hi Mark,

My understanding/experience is that longer TE reduces signal (or SNR). The
effect you mention is not surprising however. There is a paper Dr. Mori has
mentioned before, which shows that poor SNR has the effect of increasing
FA. You can search the archives on this. The increase affects areas with
low FA while those with normally high FA are less affected. In theory
having lower TE is better, but from my experience it comes a point around
60ms where eddy currents become clearly visible.
On May 15, 2014 5:55 PM, "Mark Wagshul" <Mark.Wagshul at einstein.yu.edu>
wrote:

>  Does anyone have data on this?  I have been able to find a limited
> number of papers.  There is a reference to a “dataset #4” of DTI data with
> varying TE’s on the mBIRN site but I can’t find the data on the site.  We
> have a pretty large dataset from over 60 relatively normal individuals
> (minimal to very mild TBI) with two DTI datasets at different TE’s (65 vs.
> 84ms, same b-value) which seem to be showing the opposite effect from what
> we would expecting (FA is decreasing with TE, since the diffusion times are
> longer with the longer TE set, we would expect FA to increase).  I would
> appreciate comments, or like to know if anyone has any good data on these
> effects.  Thanks,
>
>
>
> Mark
>
>
>
> _______________
>
> Mark Wagshul, PhD
> Associate Professor
> Gruss Magnetic Resonance Research Center
> Albert Einstein College of Medicine
> Bronx, NY 10461
> Ph: 718-430-4011
> Email: mark.wagshul at einstein.yu.edu
>
>
>
> [image: Einstein_LogoTagA_Blue_RGB]
>
>
>
>
>
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