[Mristudio-users] Range of RA

[Michael Bonares]

It's understandable that you're apprehensive. 
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-----Original Message-----
From: "Rajagopalan, Venkateswaran" <rajagov2 at ccf.org>
Sender: mristudio-users-bounces at mristudio.org
Date: Tue, 14 Sep 2010 10:16:45 
To: DTI Studio, ROI Editor, DiffeoMap Questions/Support<mristudio-users at mristudio.org>
Reply-To: "DTI Studio, ROI Editor,
	DiffeoMap Questions/Support" <mristudio-users at mristudio.org>
Subject: Re: [Mristudio-users] Range of RA

Thanks very much Dr. Mori and Dr.Hanqyi.
 
Venkateswaran

________________________________

From: mristudio-users-bounces at mristudio.org on behalf of susumu mori
Sent: Mon 9/13/2010 7:42 PM
To: DTI Studio, ROI Editor, DiffeoMap Questions/Support
Subject: Re: [Mristudio-users] Range of RA


I have to study a bit about RA, but FA should not be more than 1, although there is possibility if the fitting didn't work properly. For example, depending on the degree of anisotropy, noise, registration artifacts (motion, eddy current), it's possible to get negative diagonal elements, (physically impossible but mathematically possible) and FA becomes more than 1. In other words, by applying diffusion-weighting, signal increases. In DtiStudio, if diagonal elements become less than 0, they are replaced by 0, eliminating most of FA>1.


On Mon, Sep 13, 2010 at 4:20 PM, Rajagopalan, Venkateswaran <rajagov2 at ccf.org> wrote:


	Dear All,
	
	I am using recent version of DTI studio (DTISTUDIO-lates-x86.exe) to process my DTI images. I am wondering whether RA and FA maps are normalized i.e. their values range between 0-1 because in cerebral peduncle (for CST) in some of my subjects (controls) I am getting RA values above 1 and FA values close to 1 which i haven't seen while using earlier versions of DTI studio. Kindly clarify the above.
	
	Thanks in advance
	
	Venkateswaran
	

	

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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
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