[Mristudio-users] Tracking of the cingulum bundle

[Evan Fletcher]

Dear Dr. Susumu,
I signed up as a member so I could have access to your DTI data. But I did
not realize that this
would automatically put me on your mailing list. Now I am being spammed by
every question and
"thank you" from every user. I cannot find a place on the web site to
unsubscribe, even though your
emails say there is such an option. Sorry, could you please just unsubscribe
me?

Thank you,

Evan Fletcher

On Thu, Mar 12, 2009 at 3:47 PM, susumu <susumu at mri.jhu.edu> wrote:

> I suspect that your gradient table is not correct. I'm not sure but you may
> want to check your "flip x/y/z". To test this, choose the entire corpus
> callosum at the midsagittal. If it doesn't look right, you can send the
> screenshot to susumu at mri.jhu.edu.
>
> If you are using Siemens, usually you have to do 'flip-x' and for Philips,
> 'flip-z' for axial DTI with head-first, face-up.
>
> -----Original Message-----
> From: mristudio-users-bounces at mristudio.org
> [mailto:mristudio-users-bounces at mristudio.org] On Behalf Of Igor Yakushev
> Sent: Monday, March 09, 2009 2:53 PM
> To: DTI Studio, ROI Editor, Landmarker Questions/Support
> Subject: [Mristudio-users] Tracking of the cingulum bundle
>
> Dear Susumu, dear Experts,
>
> I'm trying to establish an algorithm, which would allow tracking of the
> cingulum bundle (CB) with a good reproducibility.
> I have started with the superior part of CB. First, I place two ROIs (2
> x option OR): one at the level of the splenium of the corpus callosum
> (CC) (Wakana et al., 2007 NI) and one at the border between the anterior
> 1/3 and posterior 2/3 of the CC body, please see ppt slides. According
> to Wakana et al. the second ROI should be placed at the level of the
> genu, but in this case no tracks are found between the ROIs. Relatively
> large ROIs are used in order to ensure
> initial inclusion of all voxels related to CC according to a color-coded
> map. Then, I place two smaller ROIs (2 x option AND) at the same
> locations. Fibers, whose direction roughly deviates from the direction
> of the CB, are excluded with the option NOT.
> 1) Any critique, improvements to this schema, please?
> Finally, I get a fiber track, which is substantially smaller than the
> extension of (green) voxels related to CC, please see the slides. 2) How
> should/may this be interpreted? Is this related to the procedure of the
> ROI placement?
>
> Back to tracking.. I'd like to continue tracking of CB going to its
> anterior or descending part. I start again with the option OR. Then one
> needs AND, but AND refers to all ROIs within the image, right?
> Accordingly, placement of one more ROI (option AND) e.g. at the level of
> the pons results in disappearance of the previously reconstructed
> portion of CB. 3) Possible solutions? Should one just save the
> previously reconstructed track? When all portions are tracked, it must
> be possible to save all portions as one track, isn't it?  The aim is to
> get statistics from the whole CB, not only from its portions.
>
> Many thanks!
> Igor
>
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>



-- 
Evan Fletcher, PhD
Project Scientist
IDeA Lab
Department of Neurology, UCDMC
and
Lecturer
Integrated Studies Program, UC Davis
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