[Mrtrix-discussion] GE diffusion data - gradient encoding

[Donald Tournier]

Hi Kerstin,

I had a brief look into it recently, but I can't really find a simple
answer as to exactly how the information is stored in the DICOM
headers. The more informative source is this webpage:
http://wiki.na-mic.org/Wiki/index.php/NAMIC_Wiki:DTI:DICOM_for_DWI_and_DTI

but as you can see, there's a bunch of different conventions depending
on exactly what release of the GE software produced the data.

If you want to give it a shot, you can try to modify the relevant
file, which is "lib/file/dicom/image.cpp", in the function
"Image::parse_item()". The relevant entries to set are "bvalue" and
"G". You can take a look at the "Image::decode_csa()" function to see
how it's done for Siemens data.

Let me know how you go, and send me the changes if you manage to work
it out - I'll include them in the next release.

Thanks,

Donald.


On Tue, Oct 13, 2009 at 8:44 AM, Kerstin Pannek <k.pannek1 at uq.edu.au> wrote:
> Hi all
>
> I have some GE diffusion data that I would like to run through MRtrix.
> Unfortunately I don't get the gradient encoding using mrconvert. I can get
> the encoding using a different converter, but I think that converter might
> be using a different frame of reference - I get "spiky" streamlines in the
> cingulum bundle (the data is acquired obliquely).
> Is there a way around this problem?
>
> Thanks for your help.
> Kerstin
> _______________________________________________
> Mrtrix-discussion mailing list
> Mrtrix-discussion at www.nitrc.org
> http://www.nitrc.org/mailman/listinfo/mrtrix-discussion
>



-- 
Jacques-Donald Tournier (PhD)
Brain Research Institute, Melbourne, Australia
Tel: +61 (0)3 9496 4078