Dear Martin,
> thank you very much for the explanation and the links. We work on VB17 and I can confirm that there is no option to choose between mono- or bipolar (at least I didn't find it). The multiband-sequence from UMN can do it.
> As Andreas mentioned, I also cannot download the vector-files (tested FF, Safari and Chrome on a Mac, the IE at work doesn't even show the image where I can change settings on the webpage). Maybe someone knows a workaround.
>
> So, the way I understood your comments on blip-up/down it is best to acquire two sets with opposite read-out direction, followed by DTI with whole-sphere acquisition (which I can do wit the webpage you sent us). But I cannot just scan a couple of b0-images in opposite directions (to save some time).
The "minimal" data that topup-eddy needs to correct for both susceptibility and eddy currents is
b0 blip-up-blip-down. Maybe two of each to be on the safe side
dwi sampled on the whole sphere with blip-up OR blip-down.
I have had good results with such data when there are 60 or more directions. It is POSSIBLE that it would work also for fewer directions, but I haven't tested that.
Jesper
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