<html><body bgcolor="#FFFFFF"><div>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 </div><div>whether they are inside or outside.</div><div><br></div><div>Jothy <br><br>On 14-Oct-2010, at 7:44 PM, "Scott Johnson" <<a href="mailto:Scott.Johnson@neuwave.com">Scott.Johnson@neuwave.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div>
<div class="Section1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D">Hello Xiaofeng,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D">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.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D">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 .<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D">Other than that you need to resample your dose grid at a finer
resolution still. There is a computational tradeoff.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D">Hope that helps.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"> --
Scott<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<a href="mailto:vtkusers-bounces@vtk.org">vtkusers-bounces@vtk.org</a> [mailto:vtkusers-bounces@vtk.org] <b>On Behalf Of </b>Xiaofeng
Z<br>
<b>Sent:</b> Thursday, October 14, 2010 1:10 PM<br>
<b>To:</b> <a href="mailto:jothybasu@gmail.com"><a href="mailto:jothybasu@gmail.com">jothybasu@gmail.com</a></a><br>
<b>Cc:</b> VTK<br>
<b>Subject:</b> Re: [vtkusers] Dose Volume Histogram<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">I
mean voxels that's partly inside and partly outside of the polygon.<br>
<br>
Xiaofeng Z<br>
<br>
<br>
<o:p></o:p></span></p>
<div class="MsoNormal" align="center" style="text-align:center"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<hr size="2" width="100%" align="center" id="stopSpelling">
</span></div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif"">CC: <a href="mailto:karthik.krishnan@kitware.com">karthik.krishnan@kitware.com</a>;
<a href="mailto:vtkusers@vtk.org"><a href="mailto:vtkusers@vtk.org">vtkusers@vtk.org</a></a><br>
From: <a href="mailto:jothybasu@gmail.com"><a href="mailto:jothybasu@gmail.com">jothybasu@gmail.com</a></a><br>
Subject: Re: [vtkusers] Dose Volume Histogram<br>
Date: Thu, 14 Oct 2010 18:27:23 +0100<br>
To: <a href="mailto:xf10036@hotmail.com"><a href="mailto:xf10036@hotmail.com">xf10036@hotmail.com</a></a><o:p></o:p></span></p>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">What
do you mean by partial volume?<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif"">Jothy<br>
<br>
On 14-Oct-2010, at 5:48 PM, Xiaofeng Z <<a href="mailto:xf10036@hotmail.com"><a href="mailto:xf10036@hotmail.com">xf10036@hotmail.com</a></a>>
wrote:<o:p></o:p></span></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">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.<br>
<br>
Xiaofeng Z<br>
<br>
<br>
<o:p></o:p></span></p>
<div class="MsoNormal" align="center" style="text-align:center"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<hr size="2" width="100%" align="center" id="ecxstopSpelling">
</span></div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif"">CC: <a href="mailto:karthik.krishnan@kitware.com"><a href="mailto:karthik.krishnan@kitware.com">karthik.krishnan@kitware.com</a></a>; <a href="mailto:vtkusers@vtk.org"><a href="mailto:vtkusers@vtk.org">vtkusers@vtk.org</a></a><br>
From: <a href="mailto:jothybasu@gmail.com"><a href="mailto:jothybasu@gmail.com">jothybasu@gmail.com</a></a><br>
Subject: Re: [vtkusers] Dose Volume Histogram<br>
Date: Thu, 14 Oct 2010 17:23:47 +0100<br>
To: <a href="mailto:xf10036@hotmail.com"><a href="mailto:xf10036@hotmail.com">xf10036@hotmail.com</a></a><o:p></o:p></span></p>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">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.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif"">Jothy<br>
<br>
On 14-Oct-2010, at 5:03 PM, Xiaofeng Z <<a href="mailto:xf10036@hotmail.com"><a href="mailto:xf10036@hotmail.com">xf10036@hotmail.com</a></a>>
wrote:<o:p></o:p></span></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">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.<br>
<br>
Xiaofeng Z<br>
<br>
<br>
<o:p></o:p></span></p>
<div class="MsoNormal" align="center" style="text-align:center"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<hr size="2" width="100%" align="center" id="ecxstopSpelling">
</span></div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif"">Date: Thu, 14 Oct 2010 20:14:13 +0530<br>
Subject: Re: [vtkusers] Dose Volume Histogram<br>
From: <a href="mailto:karthik.krishnan@kitware.com"><a href="mailto:karthik.krishnan@kitware.com">karthik.krishnan@kitware.com</a></a><br>
To: <a href="mailto:xf10036@hotmail.com"><a href="mailto:xf10036@hotmail.com">xf10036@hotmail.com</a></a><br>
CC: <a href="mailto:vtkusers@vtk.org"><a href="mailto:vtkusers@vtk.org">vtkusers@vtk.org</a></a><br>
<br>
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.<o:p></o:p></span></p>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">On
Thu, Oct 14, 2010 at 7:52 PM, Xiaofeng Z <<a href="mailto:xf10036@hotmail.com"><a href="mailto:xf10036@hotmail.com">xf10036@hotmail.com</a></a>> wrote:<o:p></o:p></span></p>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif"">Hello VTK users,<br>
<br>
Is there a function to generate Dose Volume Histogram?<br>
<br>
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.<br>
<br>
Thanks!<br>
<br>
Xiaofeng Z<br>
<br>
<o:p></o:p></span></p>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;
font-family:"Tahoma","sans-serif""><br>
_______________________________________________<br>
Powered by <a href="http://www.kitware.com/" target="_blank"><a href="http://www.kitware.com">www.kitware.com</a></a><br>
<br>
Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" target="_blank"><a href="http://www.kitware.com/opensource/opensource.html">http://www.kitware.com/opensource/opensource.html</a></a><br>
<br>
Please keep messages on-topic and check the VTK FAQ at: <a href="http://www.vtk.org/Wiki/VTK_FAQ" target="_blank"><a href="http://www.vtk.org/Wiki/VTK_FAQ">http://www.vtk.org/Wiki/VTK_FAQ</a></a><br>
<br>
Follow this link to subscribe/unsubscribe:<br>
<a href="http://www.vtk.org/mailman/listinfo/vtkusers" target="_blank"><a href="http://www.vtk.org/mailman/listinfo/vtkusers">http://www.vtk.org/mailman/listinfo/vtkusers</a></a><o:p></o:p></span></p>
</div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""><o:p> </o:p></span></p>
</div>
</blockquote>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">_______________________________________________<br>
Powered by <a href="http://www.kitware.com/" target="_blank"><a href="http://www.kitware.com">www.kitware.com</a></a><br>
<br>
Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" target="_blank"><a href="http://www.kitware.com/opensource/opensource.html">http://www.kitware.com/opensource/opensource.html</a></a><br>
<br>
Please keep messages on-topic and check the VTK FAQ at: <a href="http://www.vtk.org/Wiki/VTK_FAQ" target="_blank"><a href="http://www.vtk.org/Wiki/VTK_FAQ">http://www.vtk.org/Wiki/VTK_FAQ</a></a><br>
<br>
Follow this link to subscribe/unsubscribe:<br>
<a href="http://www.vtk.org/mailman/listinfo/vtkusers" target="_blank"><a href="http://www.vtk.org/mailman/listinfo/vtkusers">http://www.vtk.org/mailman/listinfo/vtkusers</a></a><o:p></o:p></span></p>
</div>
</blockquote>
</div>
</blockquote>
</div>
</div></blockquote></body></html>