<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi DTI experts,<div><br></div><div>In DTIStudio, under the DTI map tab there is an ADC Map calculation available. After the calculation, an ADC map - mean image is generated, is this the <b>apparent </b>or <b>average</b> diffusion coefficient? </div><div><br></div><div><br></div><div>Thanks,</div><div><br></div><div>Rachael</div><div><br></div><div><div style="font-family: Tahoma; "><br></div></div><div>*****************************************************************************************************************************</div><div><br></div><div>Judy, in DtiStudio, ADC (or also called MD) should be obtained from "Trace".<br><br>Trace is defined as Dxx+Dyy+Dzz. If you divide it by 3, it becomes<br>"Average diffusion constant (ADC)" or "Mean diffusivity (MD)". We like<br>to use the term "trace" because it has clear mathematical definition<br>while ADC is also used for "Apparent diffusion constant", which has a<br>different meaning from "average diffusion constant".<br><br>On Mon, Apr 11, 2011 at 11:58 AM, Judy James <<a href="mailto:jjames2@umc.edu">jjames2@umc.edu</a>> wrote:<br><blockquote type="cite">Is any one in this group aware of how to calculate ADC maps from the<br></blockquote><blockquote type="cite">original DWI images in DTI studio - not DTI images, like how to set the<br></blockquote><blockquote type="cite">gradient table in such a case?<br></blockquote><blockquote type="cite">Any input/help will be highly appreciated.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Thank you,<br></blockquote><blockquote type="cite">Judy James "<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">*********************************************************************<br></blockquote><blockquote type="cite">Judy Rose James, Ph.D.<br></blockquote><blockquote type="cite">Clinical Physicist, MR Imaging Division<br></blockquote><blockquote type="cite">Assistant Professor, Department of Radiology<br></blockquote><blockquote type="cite">University of Mississippi Medical Center<br></blockquote><blockquote type="cite">Jackson, MS - 39216<br></blockquote><blockquote type="cite">Ph: (601) 984-2585; Pager: (601) 929-2442<br></blockquote><blockquote type="cite">Email: <a href="mailto:jjames2@umc.edu">jjames2@umc.edu</a><br></blockquote><blockquote type="cite">*********************************************************************<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">________________________________<br></blockquote><blockquote type="cite">From: <a href="mailto:mristudio-users-bounces@mristudio.org">mristudio-users-bounces@mristudio.org</a><br></blockquote><blockquote type="cite">[mristudio-users-bounces@mristudio.org] On Behalf Of Jacquie Hodge<br></blockquote><blockquote type="cite">[Jacquie.Hodge@albertahealthservices.ca]<br></blockquote><blockquote type="cite">Sent: Friday, April 08, 2011 11:56 AM<br></blockquote><blockquote type="cite">To: <a href="mailto:mristudio-users@mristudio.org">mristudio-users@mristudio.org</a><br></blockquote><blockquote type="cite">Subject: [Mristudio-users] Fa values<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Good morning everyone,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I am using DTI studio for my project where I am interested in comparing the<br></blockquote><blockquote type="cite">left and right CST's in children who have suffereed injury in that area and<br></blockquote><blockquote type="cite">after reading many studies on DTI decided to compare average FA values of<br></blockquote><blockquote type="cite">the tracts as one of my variables. However, I have come across this questino<br></blockquote><blockquote type="cite">from one of my supervisors and cannot really answer it and am hoping for<br></blockquote><blockquote type="cite">your help/expertise.<br></blockquote><blockquote type="cite">Here is goes:<br></blockquote><blockquote type="cite">Is the FA value still a viable measure to look at and use to make a<br></blockquote><blockquote type="cite">correlation if you are using FA values to pull the white matter tract? It<br></blockquote><blockquote type="cite">seems like if the tract is made from FA values then you should not be able<br></blockquote><blockquote type="cite">to use the FA as an outcome variable. This question has come up as I<br></blockquote><blockquote type="cite">presented my research idea and I'm not sure how to answer it. Most studies<br></blockquote><blockquote type="cite">that use DTI use FA thresholds to pull the tracts and then also the FA<br></blockquote><blockquote type="cite">values (eg. mean FA) to make comparisons between the tracts.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I really hope that my question makes sense as I have found it very hard to<br></blockquote><blockquote type="cite">word properly.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Thank you very much,<br></blockquote><blockquote type="cite">Jacquie<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Jacquie Hodge MSc candidate in Neuroscience, BSc<br></blockquote><blockquote type="cite">Neuroscience, University of Calgary<br></blockquote><blockquote type="cite">Research Assistant, Calgary Pediatric Stroke Program<br></blockquote><blockquote type="cite">Alberta Children's Hospital<br></blockquote><blockquote type="cite">2888 Shaganappi Trail NW, Calgary, AB, Canada T3B 6A8<br></blockquote><blockquote type="cite">Phone: 403-955-7733 Fax: 403-955-2922<br></blockquote><blockquote type="cite"><a href="mailto:jacquie.hodge@albertahealthservices.ca">jacquie.hodge@albertahealthservices.ca</a><br></blockquote><blockquote type="cite">Program website:<br></blockquote><blockquote type="cite"><a href="http://www.calgaryhealthregion.ca/programs/stroke/pediatric.htm">http://www.calgaryhealthregion.ca/programs/stroke/pediatric.htm</a><br></blockquote><blockquote type="cite">________________________________<br></blockquote><blockquote type="cite">This message and any attached documents are only for the use of the intended<br></blockquote><blockquote type="cite">recipient(s), are confidential and may contain privileged information. 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<br><div><div>On Feb 23, 2011, at 4:35 AM, susumu mori wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Andreas is right.<div>So called ADC (average diffusion constant, apparent diffusion constant) and MD (mean diffusivity) are obtained by trace/3 (trace divided by 3), while the trace is (eigenvalue0+eigenvalue1+eigenvalue2).</div>
<div><br></div><div>also, axial diffusivity is same as eigenvalue0 and radial diffusivity is the average of eigenvalue1 and 2 [ (eigenvalue1+eigenvalue2)/2].<br><br><div class="gmail_quote">On Wed, Feb 23, 2011 at 8:31 AM, Andreas Buchmann <span dir="ltr"><<a href="mailto:buchmann2@wisc.edu">buchmann2@wisc.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Dear Yo,<br>
<br>
I'm using trace diffusivity, which is strongly related to mean diffusivity<br>
(I think, just multiplied with a constant factor, experts correct me if I'm<br>
wrong).<br>
<font color="#888888"><br>
Andreas<br>
</font><div class="im"><br>
<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<br>
</div><div><div></div><div class="h5"><a href="mailto:107310@ib.k.u-tokyo.ac.jp">107310@ib.k.u-tokyo.ac.jp</a><br>
Sent: Dienstag, 22. Februar 2011 19:36<br>
To: DTI Studio, ROI Editor, DiffeoMap Questions/Support<br>
Subject: Re: [Mristudio-users] radial diffusivity, mean diffusivity<br>
<br>
Dear Andreas, Ryuzo and DTI experts<br>
<br>
<br>
I also try to calculate mean diffusivity.<br>
But in DTI studio, only the radial diffusivity and ADCs can calculate at<br>
the 'Image'-tab with ROI.<br>
<br>
Is there any function to measure mean diffusivity?<br>
Please give me any suggestion.<br>
<br>
Many thanks.<br>
<br>
<br>
YO<br>
<br>
<br>
> Dear Andreas<br>
><br>
><br>
><br>
> Thank you very much for your suggestion. I will try.<br>
><br>
><br>
><br>
> Ryuzo<br>
><br>
><br>
><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 Andreas<br>
Buchmann<br>
> Sent: Monday, February 21, 2011 11:03 PM<br>
> To: 'DTI Studio, ROI Editor, DiffeoMap Questions/Support'<br>
> Subject: Re: [Mristudio-users] radial diffusivity, mean diffusivity<br>
><br>
><br>
><br>
> Dear Ryuzo,<br>
><br>
><br>
><br>
> yes, you're on the right track with (1). After the estimation, DTI-<br>
Studio<br>
> appends the images to the list of images you have, and you can see<br>
them<br>
> under the 'Image'-tab and save them with right-click on the image.<br>
><br>
><br>
><br>
> Good luck<br>
><br>
> Andreas<br>
><br>
><br>
><br>
> _____<br>
><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 hanaie<br>
> Sent: Montag, 21. Februar 2011 07:46<br>
> To: <a href="mailto:mristudio-users@mristudio.org">mristudio-users@mristudio.org</a><br>
> Subject: [Mristudio-users] radial diffusivity, mean diffusivity<br>
><br>
><br>
><br>
> Dear DTI experts<br>
><br>
><br>
><br>
> How can I do to obtain the radial diffusivity and mean diffusivity in<br>
DTI<br>
> studio?<br>
><br>
><br>
><br>
> 1. In the " Dti Map" tab, clicking "Tensor, color Map etc" button,<br>
and<br>
> checking the checkboxes "Radial", "Trace"<br>
><br>
><br>
><br>
> 2. After tensor calculation and fiber tracking, if I click "<br>
statistics"<br>
> button in the "Fiber" tab and<br>
><br>
> I choose the each image and click "go" button in the another window,<br>
can I<br>
> obtain radial and mean diffusivity?<br>
><br>
><br>
><br>
><br>
><br>
> Please give me any suggestion.<br>
><br>
><br>
><br>
> Many thanks.<br>
><br>
><br>
><br>
> Ryuzo<br>
><br>
><br>
><br>
><br>
> _______________________________________________<br>
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