Thanks a lot for the info, Michael and Andreas. Still a question on
DTI. I suppose that at VB17 software the DTI sequence uses the double
refocusing, since the TE is about 100 ms. Is there any option to turn
it off and thus shorten the TE? The only place where I would expect it
is would be possible to change is Diffusion Mode, but no option really
fit this idea.
Thanks in advance for help,
Martin
On Fri, Jun 17, 2011 at 12:33 AM, Andreas Bartsch
<[log in to unmask]> wrote:
> hi,
>>Should it also be in A>>P?
> the phase encoding of the GE fieldmaps should not matter, i.e. it can be different from the EPI, even though i tend use the same settings for the two - except that i tend to acquire a few more slices on the fieldmap.
> hth,
> andreas
>
> ________________________________________
> Von: FSL - FMRIB's Software Library [[log in to unmask]] im Auftrag von Martin Kavec [[log in to unmask]]
> Gesendet: Donnerstag, 16. Juni 2011 23:20
> An: [log in to unmask]
> Betreff: [FSL] Field map for fMRI and DTI on Siemens
>
> Hi all,
>
> Before I start re-inventing a wheel: I see there is a field mapping
> sequence on Siemens Verio VB17. Anybody has experience in using it for
> unwarping fMRI and DTI (e.g. in the presurgical protocol)?
> Interestingly, the default fMRI sequences have A>>P phase encoding
> direction, but the field mapping sequence is encoded in R>>L
> direction. Should it also be in A>>P? How do I know the field map
> unwarp is being applied on the fMRI and DTI series?
>
> Thanks for sharing your experiences.
>
> Cheers,
>
> Martin
|