Dear Dr. Susumu,<div><br></div><div>I signed up as a member so I could have access to your DTI data. But I did not realize that this</div><div>would automatically put me on your mailing list. Now I am being spammed by every question and</div>
<div>"thank you" from every user. I cannot find a place on the web site to unsubscribe, even though your</div><div>emails say there is such an option. Sorry, could you please just unsubscribe me?</div><div><br></div>
<div>Thank you,</div><div><br></div><div>Evan Fletcher<br><br><div class="gmail_quote">On Thu, Mar 12, 2009 at 3:47 PM, susumu <span dir="ltr"><<a href="mailto:susumu@mri.jhu.edu">susumu@mri.jhu.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">I suspect that your gradient table is not correct. I'm not sure but you may<br>
want to check your "flip x/y/z". To test this, choose the entire corpus<br>
callosum at the midsagittal. If it doesn't look right, you can send the<br>
screenshot to <a href="mailto:susumu@mri.jhu.edu">susumu@mri.jhu.edu</a>.<br>
<br>
If you are using Siemens, usually you have to do 'flip-x' and for Philips,<br>
'flip-z' for axial DTI with head-first, face-up.<br>
<br>
-----Original Message-----<br>
From: <a href="mailto:mristudio-users-bounces@mristudio.org">mristudio-users-bounces@mristudio.org</a><br>
[mailto:<a href="mailto:mristudio-users-bounces@mristudio.org">mristudio-users-bounces@mristudio.org</a>] On Behalf Of Igor Yakushev<br>
Sent: Monday, March 09, 2009 2:53 PM<br>
To: DTI Studio, ROI Editor, Landmarker Questions/Support<br>
Subject: [Mristudio-users] Tracking of the cingulum bundle<br>
<br>
Dear Susumu, dear Experts,<br>
<br>
I'm trying to establish an algorithm, which would allow tracking of the<br>
cingulum bundle (CB) with a good reproducibility.<br>
I have started with the superior part of CB. First, I place two ROIs (2<br>
x option OR): one at the level of the splenium of the corpus callosum<br>
(CC) (Wakana et al., 2007 NI) and one at the border between the anterior<br>
1/3 and posterior 2/3 of the CC body, please see ppt slides. According<br>
to Wakana et al. the second ROI should be placed at the level of the<br>
genu, but in this case no tracks are found between the ROIs. Relatively<br>
large ROIs are used in order to ensure<br>
initial inclusion of all voxels related to CC according to a color-coded<br>
map. Then, I place two smaller ROIs (2 x option AND) at the same<br>
locations. Fibers, whose direction roughly deviates from the direction<br>
of the CB, are excluded with the option NOT.<br>
1) Any critique, improvements to this schema, please?<br>
Finally, I get a fiber track, which is substantially smaller than the<br>
extension of (green) voxels related to CC, please see the slides. 2) How<br>
should/may this be interpreted? Is this related to the procedure of the<br>
ROI placement?<br>
<br>
Back to tracking.. I'd like to continue tracking of CB going to its<br>
anterior or descending part. I start again with the option OR. Then one<br>
needs AND, but AND refers to all ROIs within the image, right?<br>
Accordingly, placement of one more ROI (option AND) e.g. at the level of<br>
the pons results in disappearance of the previously reconstructed<br>
portion of CB. 3) Possible solutions? Should one just save the<br>
previously reconstructed track? When all portions are tracked, it must<br>
be possible to save all portions as one track, isn't it? The aim is to<br>
get statistics from the whole CB, not only from its portions.<br>
<br>
Many thanks!<br>
Igor<br>
<br>
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</blockquote></div><br><br clear="all"><br>-- <br>Evan Fletcher, PhD<br>Project Scientist<br>IDeA Lab<br>Department of Neurology, UCDMC<br>and<br>Lecturer<br>Integrated Studies Program, UC Davis<br>
</div>