Difference between revisions of "Hageman:NAMICFluidMechDTITractography"

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(New page: Return to 2008_Winter_Project_Week, 2008 Winter Fluid Mechanics DTI Tractography Project Page __NOTOC__ = Fluid Mechanics Bas...)
 
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Return to [[2008_Winter_Project_Week]], [[2008_Winter_Project_Week:Fluid_Mechanics_Tractography|2008 Winter Fluid Mechanics DTI Tractography Project Page]]
 
 
__NOTOC__
 
__NOTOC__
 
= Fluid Mechanics Based DTI Tractography =
 
= Fluid Mechanics Based DTI Tractography =
  
Here write a brief overview of your project.  
+
== Overview ==
 +
In this paper, we present a novel method modeled on the dynamics of a viscous fluid described by the second order non-linear Navier-Stokes equations, an extension of previous work by our group \cite{hageman-toga:2006}  The Navier-Stokes equations govern flow for a viscous Newtonian fluid, a fluid whose internal stress forces are linearly related to its strain forces \cite{versteeg}.  However, even though these equations are most commonly seen in the context of fluid mechanics, they have been shown to be successful in modeling a large number of diverse physical phenomena.  Our second order nonlinear-based approach is an extension of previous linear PDE methods.  We hypothesize that our method will have a better performance than competing tractography methods in the presence of noise and it will not require a white matter mask, commonly used by other PDE-based methods.  This is because our model contains a viscous force not present in previous methods, represented as an additional convection term in the PDE.  We model local viscosity of the fluid as a function of the local intervoxel and intravoxel anisotropy in the corresponding DTI image volume.  The incorporation of this convection term in our flow field calculation allows us to closely couple the magnitude of the fluid velocity to the magnitude of the underlying anisotropy of the DTI tensor field, providing a dampening force in background areas, such as gray matter and CSF.  This eliminates the need for the white matter mask used by other PDE-based methods to prevent the model from entering these areas.  To compute an estimate of the most likely connection path between two regions in the brain, we simulate the flow of an artificial fluid between those two points through a volume whose dimensions, pressure, and local viscosity are derived from the underlying DTI data.  We then numerically solve for the fluid velocity vector field.  The estimated connection path is then computed by finding the optimal path through the fluid velocity that simultaneously maximizes both the fluid velocity and its gradient.  We apply our method to DTI volumes from normal human subjects and to computer-generated DTI phantoms to validate our approach.    
  
= Description =
+
== Description ==
  
 
Descriptions and progress go here.  Here is where you write the bulk of your project.  The details given in this Template Project page represent the minimal amount of information that should be included for each project.  By housing all of the Project information on a single page, Wiki maintanence is reduced.  Now we can link to this page from several other places in the Wiki, such as each site's Site Page, the NA-MIC Collaborations page, Project Week pages, and from the externally visible NA-MIC webpage.
 
Descriptions and progress go here.  Here is where you write the bulk of your project.  The details given in this Template Project page represent the minimal amount of information that should be included for each project.  By housing all of the Project information on a single page, Wiki maintanence is reduced.  Now we can link to this page from several other places in the Wiki, such as each site's Site Page, the NA-MIC Collaborations page, Project Week pages, and from the externally visible NA-MIC webpage.
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Write access for the publications database will be given out to a few select individuals.  If you do not currently have write access to the publications database, please send the following information to John Melonakos at (jmelonak at ece.gatech.edu), for "In Print" publications only:  1) the final printed version of the PDF, 2) the bibtex entry for the publication, 3) the NA-MIC Project URLs against which this publication should be linked, and 4) any other files that you would like to add to the publication database for this publication.
 
Write access for the publications database will be given out to a few select individuals.  If you do not currently have write access to the publications database, please send the following information to John Melonakos at (jmelonak at ece.gatech.edu), for "In Print" publications only:  1) the final printed version of the PDF, 2) the bibtex entry for the publication, 3) the NA-MIC Project URLs against which this publication should be linked, and 4) any other files that you would like to add to the publication database for this publication.
  
= Key Investigators =
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== Key Investigators ==
  
 
* Site1: Person 1, Person 2, Person 3
 
* Site1: Person 1, Person 2, Person 3
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* Site3: Person 1, Person 2, Person 3, Person 4
 
* Site3: Person 1, Person 2, Person 3, Person 4
  
= Publications =
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== Publications ==
  
 
''In Print''
 
''In Print''
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* Author1, Author2. "Title2". Publisher Info, etc.
 
* Author1, Author2. "Title2". Publisher Info, etc.
  
= Links =
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== Links ==
  
 
* Link1
 
* Link1
 
* Link2
 
* Link2
  
  Project Week Results:  [[blah|Jan 2006]], [[blah|Jun 2007]]
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  Project Week Results:  [[2008_Winter_Project_Week:Fluid_Mechanics_Tractography|2008 Winter]]

Revision as of 11:58, 14 February 2008

Home < Hageman:NAMICFluidMechDTITractography

Fluid Mechanics Based DTI Tractography

Overview

In this paper, we present a novel method modeled on the dynamics of a viscous fluid described by the second order non-linear Navier-Stokes equations, an extension of previous work by our group \cite{hageman-toga:2006} The Navier-Stokes equations govern flow for a viscous Newtonian fluid, a fluid whose internal stress forces are linearly related to its strain forces \cite{versteeg}. However, even though these equations are most commonly seen in the context of fluid mechanics, they have been shown to be successful in modeling a large number of diverse physical phenomena. Our second order nonlinear-based approach is an extension of previous linear PDE methods. We hypothesize that our method will have a better performance than competing tractography methods in the presence of noise and it will not require a white matter mask, commonly used by other PDE-based methods. This is because our model contains a viscous force not present in previous methods, represented as an additional convection term in the PDE. We model local viscosity of the fluid as a function of the local intervoxel and intravoxel anisotropy in the corresponding DTI image volume. The incorporation of this convection term in our flow field calculation allows us to closely couple the magnitude of the fluid velocity to the magnitude of the underlying anisotropy of the DTI tensor field, providing a dampening force in background areas, such as gray matter and CSF. This eliminates the need for the white matter mask used by other PDE-based methods to prevent the model from entering these areas. To compute an estimate of the most likely connection path between two regions in the brain, we simulate the flow of an artificial fluid between those two points through a volume whose dimensions, pressure, and local viscosity are derived from the underlying DTI data. We then numerically solve for the fluid velocity vector field. The estimated connection path is then computed by finding the optimal path through the fluid velocity that simultaneously maximizes both the fluid velocity and its gradient. We apply our method to DTI volumes from normal human subjects and to computer-generated DTI phantoms to validate our approach.

Description

Descriptions and progress go here. Here is where you write the bulk of your project. The details given in this Template Project page represent the minimal amount of information that should be included for each project. By housing all of the Project information on a single page, Wiki maintanence is reduced. Now we can link to this page from several other places in the Wiki, such as each site's Site Page, the NA-MIC Collaborations page, Project Week pages, and from the externally visible NA-MIC webpage.

A Special Note: Dashed Boxes

If a blank space is the first character for a Wiki line, the following text will be listed in a dashed box, such as the one appearing at the top of each Site and Project Page containing the links to go back to previous pages. Note, that if you entered the edit mode via any of the subheading edit links, upon a "Save page" the blank space at the top of the Wiki page will be removed. Therefore, you will need to manually add the blank space to maintain the dashed text box at the top of the page. Dashed boxes are also used at the bottom of the Project Pages to link to applicable Project Week pages.

A Special Note about Publications

"In Press" publications will be listed in two places on the Wiki (in the "In Press" sections on the Publications page and on the appropriate Project page(s)). "In Press" publications will not be added to the Publications DB.

"In Print" publications will be added to the Publications DB with the appropriate Grant number (linking it to the search on the Publications DB) and with the appropriate Project page URL added as a keyword (linking it into the Project page). Once the publication is added to the DB, it will be removed from it's listing in the two "In Press" sections mentioned above.

Write access for the publications database will be given out to a few select individuals. If you do not currently have write access to the publications database, please send the following information to John Melonakos at (jmelonak at ece.gatech.edu), for "In Print" publications only: 1) the final printed version of the PDF, 2) the bibtex entry for the publication, 3) the NA-MIC Project URLs against which this publication should be linked, and 4) any other files that you would like to add to the publication database for this publication.

Key Investigators

  • Site1: Person 1, Person 2, Person 3
  • Site2: Person 1
  • Site3: Person 1, Person 2, Person 3, Person 4

Publications

In Print

In Press

  • Author1, Author2. "Title1". Publisher Info, etc.
  • Author1, Author2. "Title2". Publisher Info, etc.

Links

  • Link1
  • Link2
Project Week Results:  2008 Winter