[Neuroimaging] [Dipy] Scanning parameters of Dipy's sample data Sherbrooke's 3 shells

[Rafael Henriques]

Hi all,

I am currently participating in Google Summer of Code and I am implementing
on Dipy a module for diffusion kurtosis imaging, a technique useful to
probe in vivo tissue heterogeneity and complexity.

Our first results are looking very good (you can see them here:
http://gsoc2015dipydki.blogspot.co.uk/2015/07/rnh-post-6-mid-term-summary.html),
however when I try to process the Dipy's multi-shell dataset example Sherbrooke
3 shells, kurtosis measures seem to be widely corrupted by implausible high
negative values (black regions on the images of the following link:
 http://gsoc2015dipydki.blogspot.co.uk/2015/07/rnh-post-7-artifacts-in-dipys-sample.html
<http://gsoc2015dipydki.blogspot.co.uk/2015/07/rnh-post-7-artifacts-in-dipys-sample.html>
).

Implausible high negative values of kurtosis are a common artifact on DKI,
however, given the data’s b-value and number of gradient directions, I was
not expecting having implausible negative values in almost all brain image
voxels. To try understanding why diffusion kurtosis is not working on this
dataset, I was wondering if anyone knows the full scanning parameters of
this dataset?

Many thanks in advance,

Rafael
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