Difference between revisions of "Documentation/4.1/Modules/BRAINSMush"

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Revision as of 05:03, 4 May 2010

Home < Documentation < 4.1 < Modules < BRAINSMush

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Gallery of New Features


BRAINSMush

BRAINSMush

User Interface
T1 Image
T2 Image
Mush Image
Mush Brain Extraction Mask(Coronal)
Mush Brain Extraction Mask(Sagittal)

General Information

Module Type & Category

Type: CLI

Category: Segmentation

Authors, Collaborators & Contact

  • Ronald Pierson, University of Iowa
  • Gregory Harris, University of Iowa
  • Hans Johnson, PhD: University of Iowa
  • Steven A. Dunn: University of Iowa
  • Vincent Magnotta, PhD: University of Iowa
  • Contacts: Vincent Magnotta, vincent-magnotta@uiowa.edu; Steven Dunn, steven-dunn@uiowa.edu

Module Description

BRAINSMush uses the Maximize Uniformity Summation Heuristic(MUSH) optimizer, as developed at the University of Iowa, to extract the brain and surface CSF from a multi-modal imaging study. It forms a linear combination of multi-modal MR imaging data to make the signal intensity within the brain as uniform as possible. This resulting image is then thresholded to obtain the brain and surface CSF region.

MUSH uses a T1-weighted and T2-weighted image as its inputs, and their mean and variance are calculated. A linear combination is then found that approaches the desired mean and variance( by default 1000.0 and 0.0, respectively) by only varying the coefficients a and b in the following equation:


[math]Mush = {\color{red}a}T1 + {\color{blue}b}T2[/math]


Within the region of interest, the MUSH optimizer finds the number of voxels, the sum voxels and the sum of squares for both images separately. Then a 2 by 2 Levenberg-Marquardt optimizer repeatedly reconstructs the mean and variance of the mixture model corresponding to the weighted sum image of coefficients a and b. This is very fast because each step only involves the calculation of two jointly weighted statistics. The result of optimization is the pair of linear coefficients that minimizes the sum of squares error:


[math]Error = (mean - 1000.0)^2 + (variance - 0.0)^2[/math]


The image is thresholded by the mean signal intensity plus-or-minus five standard deviations.

This method was applied to a sample of 20 MR brain scans and its results were compared to those obtained by 3dSkullStrip, 3dIntracranial, BET and BET2. The average Jaccard metrics for the twenty subjects was 0.66(BET), 0.61(BET2), 0.88(3dIntracranial), 0.91(3dSkullStrip) and 0.94(MUSH).

Usage

Use Case

The processing involved in the module is not designed for interactive use. It may take up to 15 minutes( or longer, depending on processor speed) to process a dataset.

Quick Tour of Features and Use

A list panels in the interface, their features, what they mean, and how to use them. For instance:

* Input panel:

Specify the two input images(typically T1 and T2) as well as an optional ROI mask. This mask can be specified to aid the creation of the MUSH image, but is not necessary. Providing an ROI mask occasionally produces greater contrast in the output MUSH image(by constraining the pixels over which the mean and variance are calculated), so it is provided as an option for those who want it.

Input Panel
* Parameters panel:
* Output panel:
Output Panel
* Viewing panel:

Development

Notes from the Developer(s)

Algorithms used, library classes depended upon, use cases, etc.

Dependencies

Other modules or packages that are required for this module's use.

Tests

On the Dashboard, these tests verify that the module is working on various platforms:

Known bugs

Links to known bugs in the Slicer3 bug tracker


Usability issues

Follow this link to the Slicer3 bug tracker. Please select the usability issue category when browsing or contributing.

Source code & documentation

Links to the module's source code:

Source code:

Doxygen documentation:

More Information

Acknowledgment

Include funding and other support here.

References

Publications related to this module go here. Links to pdfs would be useful.