[Insight-users] Chest CT Segmentation

Luis Ibanez luis . ibanez at kitware . com
Mon, 08 Dec 2003 20:19:38 -0500


Hi Henky,

Here are some ITK algorithms that you may
want to try out for segmenting Lung from CT.


1)  Watersheds.
     Please look at the example in the software guide

     http://www . itk . org/ItkSoftwareGuide . pdf

     Section 9.2 pdf-page 356.

     You should compute the GradientMagnitude of the
     CT image and then run Watersheds in this output.


2)  ThresholdSegmentationLevelSet
     You will find this method described in
     http://www . itk . org/ItkSoftwareGuide . pdf
     Section 9.3.4, pdf-page 386.



3)  FastMarchingLevelSet
     It is described in Section 9.3.1, pdf-page 365.
     http://www . itk . org/ItkSoftwareGuide . pdf
     If you find that FastMarching produces leaks
     you can move to refine the level set using
     the GeodesicActiveContour filter described in
     Section 9.3.3, pdf-page 380.



An easy way to experiment with these algorithms
is ot use the free version of VolView and run
the ITK plugins that you will find in the
"View->Filters" menu.

You can download VolView for free from

   http://www . kitware . com/products/volview . html

Once you find good parameters for segmenting your data
set you can reproduce a pipeline in your own application.


You will also find useful to look at the applications
available in the InsightApplications checkout.

In particular to:

   - The SegmentationEditor (Watershed)
   - SNAP (manual segmentation + Level Sets)


NOTE that LevelSet algorithms expect your data to be
represented with isotropic pixels. Chest CT is usually
anisotropic. You may want to use the program

  Insight/Examples/Filtering/ResampleVolumesToBeIsotropic.cxx

in order to convert your CT to isotropic pixels.



Please let us know if you have further questions,



Thanks,



    Luis



------------------------------
Henky Wibowo wrote:

> Hello,
> 
> Can anyone give me a suggestion as which segmentation algorithm would do
> well in segmenting the lung region in a stack of CT scan?
> 
> Thanks,
> 
> Henky
> 
> 
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