[Insight-users] enhancing plate like structures (by modifying itkHessianSmoothed3DToVesselnessMeasureImageFilter)

[Ho Cheung]

Hi Dr. Grothausmann,

The measure in ITK appears to be based on Sato (http://www.spl.harvard.edu/archive/spl-pre2007/pages/papers/yoshi/node3.html#SECTION00021000000000000000) and I don't see an easy way to modify it so that it detects plate like structures instead of line like structures.

If speed is not a major concern for you, may I suggest you implement a similar measure? Frangi's original vesselness enhancement formula (http://www.dtic.upf.edu/~afrangi/articles/miccai1998.pdf) can be easily modified for what you need and is based on Eigenvalues like Sato.

According to equations 10, 11, 12, 13 in Frangi's paper and my interpretation of what the measures do, what you need is high Ra, Rb, and S values, so the formula becomes:

V = [1 - exp(-Ra^2/2a^2)][1 - exp(-Rb^2/2b^2)][1 - exp(-S^2/2c62)]

Hope, this helps,

Ho Cheung
Research Assistant
Bio-Image Analytics Laboratory - University of Houston
(832) 215-6347



On Sep 5, 2012, at 3:36 AM, Dr. Roman Grothausmann <grothausmann.roman at mh-hannover.de> wrote:

> Dear mailing list members, dear Luca,
> 
> 
> Recently I was trying to enhance vascular structures from airways with the vessel enhancement filters from ITK (objectness and vessel enhancement). The  problem is that these vessels are not filled in the tomograms our imaging technique yields. Only the airway walls are imaged, which corresponds to an uneven 2D surface. Since it is only a 3D not an ND problem, I tried to modify itkHessianSmoothed3DToVesselnessMeasureImageFilter to enhance not vessels (1D) structures but plates/walls. Therefore I exchanged lambda 1 and 3 in the weighting function. Sadly, I could not get the filter  to enhance the airway walls.
> Have I missed anything or would enhancing plateness this way only work for not-curved planes?
> 
> 
> Here the important part of the diff of my changes:
> 
> diff -au itk/IJ-Vessel_Enhancement_Diffusion.1/itkHessianSmoothed3DToVesselnessMeasureImageFilter.txx itk/plateness3D_01/itkHessianSmoothed3DToPlatenessMeasureImageFilter.txx
> 
> 
> 
> +      ////swap Lambda1 and Lambda3 to enhance "plateness"
> +      double swap_tmp= Lambda1;
> +      Lambda3= Lambda1;
> +      Lambda1= swap_tmp;
> +      ///swapping done
> +
>       double Lambda1Abs = vnl_math_abs( Lambda1 );
>       double Lambda2Abs = vnl_math_abs( Lambda2 );
>       double Lambda3Abs = vnl_math_abs( Lambda3 );
> @@ -162,14 +168,13 @@
>       double vesMeasure_3  =
>          ( 1 - vcl_exp( -1.0 * (( vnl_math_sqr( S )) / ( 2.0 * ( GammaSqr)))));
> 
> -      double vesMeasure_4  =
> -         vcl_exp ( -1.0 * ( 2.0 * vnl_math_sqr( m_C )) /
> -                                   ( Lambda2Abs * (Lambda3Sqr)));
> +      double vesMeasure_4  = 1; ////plateness for now not smoothed
> +      //double vesMeasure_4  = vcl_exp ( -1.0 * ( 2.0 * vnl_math_sqr( m_C )) / ( Lambda2Abs * (Lambda3Sqr))); ////check if this makes sense for plateness
> 
> 
> Many thanks for any help or hints.
> Roman
> 
> -- 
> Dr. Roman Grothausmann
> 
> Tomographie und Digitale Bildverarbeitung
> Tomography and Digital Image Analysis
> 
> Institut für Funktionelle und Angewandte Anatomie, OE 4120
> Medizinische Hochschule Hannover
> Carl-Neuberg-Str. 1
> 30625 Hannover
> 
> Tel. +49 511 532-9574
> _____________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
> 
> Kitware offers ITK Training Courses, for more information visit:
> http://www.kitware.com/products/protraining.php
> 
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.itk.org/mailman/listinfo/insight-users