[vtkusers] Dose Volume Histogram

[Jothy]

Weighting of the voxels seems to be a good idea, but I am not sure whether you will be able to know the voxels on surface. Most of the methods says only 
whether they are inside or outside.

Jothy 

On 14-Oct-2010, at 7:44 PM, "Scott Johnson" <Scott.Johnson at neuwave.com> wrote:

> Hello Xiaofeng,
> 
>  
> 
> You could minimize the partial volume by sampling into the dose grid at the resolution of the CT voxels.  For example, you iterate through the CT voxels for which you wish to create your DVH.  Map  the center of that CT voxel position and sample into the Dose Grid to find the dose value at that same position.  Then assume that dose value occupies the entire CT voxel space.  That value goes into your DVH.
> 
>  
> 
> You can further minimize the partial volume effect by weighting the voxels at the edges of your ROI.  As a swag, multiply the voxel weight of an edge voxel by 0.5 .
> 
>  
> 
> Other than that you need to resample your dose grid at a finer resolution still.  There is a computational tradeoff.
> 
>  
> 
> Hope that helps.
> 
>  
> 
>                                 -- Scott
> 
>  
> 
> From: vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] On Behalf Of Xiaofeng Z
> Sent: Thursday, October 14, 2010 1:10 PM
> To: jothybasu at gmail.com
> Cc: VTK
> Subject: Re: [vtkusers] Dose Volume Histogram
> 
>  
> 
> I mean voxels that's partly inside and partly outside of the polygon.
> 
> Xiaofeng Z
> 
> 
>  
> 
> CC: karthik.krishnan at kitware.com; vtkusers at vtk.org
> From: jothybasu at gmail.com
> Subject: Re: [vtkusers] Dose Volume Histogram
> Date: Thu, 14 Oct 2010 18:27:23 +0100
> To: xf10036 at hotmail.com
> 
> What do you mean by partial volume?
> 
>  
> 
> Jothy
> 
> On 14-Oct-2010, at 5:48 PM, Xiaofeng Z <xf10036 at hotmail.com> wrote:
> 
> Do you take into account of partial volume?  The dose grid is typically very coarse, I don't think the partial volume can be ignored.
> 
> Xiaofeng Z
> 
> 
>  
> 
> CC: karthik.krishnan at kitware.com; vtkusers at vtk.org
> From: jothybasu at gmail.com
> Subject: Re: [vtkusers] Dose Volume Histogram
> Date: Thu, 14 Oct 2010 17:23:47 +0100
> To: xf10036 at hotmail.com
> 
> If you are speaking from the radiotherapy point of view,it should be done in a different way from what krishnan told. You should first use point-in-polygon method(which is available in vtkPolygon class) to find the voxels inside the structure and using the voxel indices, you could get their respective dose values and use a binning/histogram to bin the dose values to get the dvh along with their volumes.
> 
>  
> 
> Jothy
> 
> On 14-Oct-2010, at 5:03 PM, Xiaofeng Z <xf10036 at hotmail.com> wrote:
> 
> Hi Karthik,  Thanks for your answer.  The problem is that I also have a contour and only the volume (area) inside the contour should be included the histogram.
> 
> Xiaofeng Z
> 
> 
>  
> 
> Date: Thu, 14 Oct 2010 20:14:13 +0530
> Subject: Re: [vtkusers] Dose Volume Histogram
> From: karthik.krishnan at kitware.com
> To: xf10036 at hotmail.com
> CC: vtkusers at vtk.org
> 
> No there isn't, but it should be relatively straightforward. On your dose image,  run vtkContourFilter with isovalues, that evenly split your scalar range into the desired number of bins. Then use vtkMassProperties to compute the area within each dose isocontour and use the charting capability to plot.
> 
> On Thu, Oct 14, 2010 at 7:52 PM, Xiaofeng Z <xf10036 at hotmail.com> wrote:
> 
> Hello VTK users,
>  
> Is there a function to generate Dose Volume Histogram?
>  
> A Dose Volume Histogram is, in essence, a histogram of the area vs. intensity within an arbitrary contour i.e. the contour points are not always at pixel center.
>  
> Thanks!
> 
> Xiaofeng Z
> 
> 
> 
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
> 
>  
> 
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20101014/e5729514/attachment.htm>