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

[Maxime Descoteaux]

Hi Rafael,

I will try to find the information for you but I fear it will be difficult
as these datasets are at least 4 years old and from an old 1.5T Siemens
scanner.

You would want TE/TR, delta, Delta, etc? I know that I will not have delta,
Delta. I might be able to find TR, TE and other basic parameters.

Best

Max

On Wed, Jul 8, 2015 at 3:46 AM, Rafael Henriques <rafaelnh21 at gmail.com>
wrote:

> 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
>
> _______________________________________________
> Neuroimaging mailing list
> Neuroimaging at python.org
> https://mail.python.org/mailman/listinfo/neuroimaging
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/neuroimaging/attachments/20150708/7f21abe2/attachment.html>