Dear Gabor,
>
> Thanks a lot. I've checked http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/EDDY/UsersGuide. However, this site details an example where in the P->A direction only a b0 is measured. When I'd like to increase the SNR which is the better option? Is it worth to repeat the whole DTI (e.g. b0+30 directions) in the P->A direction, or to acquire 2 times the whole DTI only in the A->P direction and measure only two B0s in the P->A direction right before the two DTIs in the A->P direction?
If you are anyway planning to repeat the directions in order to improve the SNR it is better to acquire 30 A->P and 30 P->A.
If you plan to use the data for something that benefits from high angular sampling (like for example tractography) it would be even better to stagger them so that the total 60 acquisitions samples the diffusion sphere evenly and so that the A->P and the P->A are well mixed on the sphere.
Jesper
>
>
> Best regards,
> Gabor
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