Hi everyone, I’m trying to use Maurer 3D distance map to calculate the difference in size of a tumor before and after procedure (to estimate margin). I applied the signedmaurerdistancemap filter to the pre-procedure tumor, but how do I superimpose the post-procedure tumor onto this map and pull out…

I think the issue is not the segmentation node but the segment, because otherwise the error message would be “AttributeError: ‘NoneType’ object has no attribute ‘GetSegmentation’”. But in any case, any string literals in sample code should be double checked for your use case, because every Slicer sc…

You can use Segment Comparison module and I think ChangeTracker can do some quantifications like this, too. Of course you can compute the distance map and do your custom visualization, too. Just choose the overlay as foreground volume and go to Volumes module to threshold the distance map and custo…

Thank you for replying! I can’t seem to figure out how to use the Volume module to calculate the distance. I set the post-procedure tumor volume as the back ground, the pre-procedure tumor with 3D map as the foreground. The active volume is also set as the pre-procedure tumor volume with 3D map. H…

What exact would you like to compute? If you only need tumor volumes then you can get it from Segment Statistics module (after you segmented the tumor using Segment Editor).

I would like to compute the difference in distance between the pre procedure volume and the post procedure volume (to see if the procedure achieved adequate margin). I had some results using the Segment Comparison as you suggested (thank you!). I was just trying to learn how to compute the margin us…

Distance is computed by Segment Comparison module. It computes metrics like maximum, 95th percentile, and median of the distance distribution.

Thank you for your suggestion, I will learn more about the Segment Comparison module!

I have been able to use Segment Comparison and got the maximum, 95th, and median distance just like you described. However, is there a way to extract all the distances between the two segments instead of just the three metrics above? I want to assess if the treatment zone has achieved enough margin …

@cpinter Could you give advice on how to get the complete histogram?

Note that you can also export segments to model nodes and use Model to Model Distance extension to get a model that has the computed distances for each point. You can display this model as a colored surface, you can export distances to numpy and compute basic stats, histogram, etc. and you can also …

There’s a class that can get the histogram of the model distances called vtkPolyDataDistanceHistogramFilter . There is no user interface for that so python scripting is necessary. If you use Segment Editor then you can get the poly data from the segments, feed them to this class, and get the output a…

Calculating distance using Maurer distance map

Support

ytaneja (Yash) September 18, 2019, 9:59pm 20

What are the units that you have in the histogram? 1100 (pixels, mm, microns?) difference in the models

Thank you!

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Calculating distance using Maurer distance map

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