[Mristudio-users] new option save fiber density

[Zhang, Aifeng]

Dear DtiStudio,

A further question on this topic:
Is the statistics (by clicking the statistics button in DtiStudio) given along the select fibers density-weighted or not?

thanks,
Aifeng
From: mristudio-users-bounces at mristudio.org [mailto:mristudio-users-bounces at mristudio.org] On Behalf Of susumu mori
Sent: Saturday, July 24, 2010 7:57 AM
To: DTI Studio, ROI Editor, DiffeoMap Questions/Support; Hangyi Jiang
Subject: Re: [Mristudio-users] new option save fiber density

Hi Venkat,

After fiber tracking, it is a common practice to quantify the results. For the quantification, the streamline information of the tractography needs to be converted to pixel information. For this conversion, the simplest way is to use 1/0 binarilzation. If a pixel contains a streamline, it becomes 1 and if not, remains 0. This is basically a masking, which can be applied to, for example, a FA map and get a FA value of the tract. You can also count the number of pixels with "1" and use it as the tract volume.

One problem of this simple approach is that even if a pixel contains 10 streamlines, the pixel becomes "1", which is the same as another pixel that contains only 1 streamline. Namely, during the binalization, information about the density of the streamline is lost. I believe (Hangyi, please correct me if I'm wrong) "fiber density map" tells how many streamlines were there in each pixel. You can potentially use it to get, for example, density-weighted FA value, in which pixels that contain more streamlines are more weighted than those contain only 1 streamline.
On Fri, Jul 23, 2010 at 6:19 PM, Rajagopalan, Venkateswaran <rajagov2 at ccf.org<mailto:rajagov2 at ccf.org>> wrote:


Dear All,

I am using DTIstudio_latest_x86.exe after fiber tractography I notices a new option named "save fiber density map" (normalized and non normalized). I am wondering what information does this fiber density map convey and how this information can be used for instance to compare between two groups. How the map is normalized.

Thanks

Venkat

===================================
P Please consider the environment before printing this e-mail









Cleveland Clinic is ranked one of the top hospitals

in America by U.S.News & World Report (2009).

Visit us online at http://www.clevelandclinic.org for

a complete listing of our services, staff and

locations.





Confidentiality Note:  This message is intended for use

only by the individual or entity to which it is addressed

and may contain information that is privileged,

confidential, and exempt from disclosure under applicable

law.  If the reader of this message is not the intended

recipient or the employee or agent responsible for

delivering the message to the intended recipient, you are

hereby notified that any dissemination, distribution or

copying of this communication is strictly prohibited.  If

you have received this communication in error,  please

contact the sender immediately and destroy the material in

its entirety, whether electronic or hard copy.  Thank you.

_______________________________________________
mristudio-users mailing list
mristudio-users at mristudio.org<mailto:mristudio-users at mristudio.org>
http://lists.mristudio.org/mailman/listinfo/
Unsubscribe, send a blank email to: mristudio-users-unsubscribe at mristudio.org<mailto:mristudio-users-unsubscribe at mristudio.org>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.mristudio.org/pipermail/mristudio-users/attachments/20100818/0daafada/attachment-0001.html