how to plot the dose volume histogram using dose map and the mask?

Hello,

I'm trying to calculate the DVH using MATLAB. I already have create the mask (RTstruc) and the dose map (RTdose). I created meghgrids for both the mask and and the dose map and I resized the dose map to match the mask using interp3 but the problem is when I masked this interpolated dose map to only include that mask, the masked dose map is giving me NaN values, even though the interpolated dose map and the mask are correctly defined. I visulaized the dose map and the mask and they seem not aligned.

[DGM]

We don't know how you used interp3(), or what you did to create or apply the mask. We don't know what the array dimensions are or what you mean when you say "not aligned". It's also not clear why content misalignment would cause an addressing operation to output NaNs which were not in the array being addressed.

You need to provide more information.

Answer 1

[Sanju]

Hi Farah,

It seems like the issue you're facing is related to the alignment of the dose map and the mask. When interpolating the dose map, it's important to ensure that the interpolation is done correctly to match the grid of the mask. Here are a few suggestions to address this issue,

• Check the grid spacing and dimensions of both the mask and the dose map. Make sure they are consistent and match each other.
• Verify that the interpolation method used in interp3 is appropriate for your data. You may need to experiment with different interpolation methods (e.g., linear, nearest neighbor, cubic) to find the one that works best for your case.
• Double-check the order of the dimensions in the dose map and the mask. It's possible that they are not aligned properly. You can use the permute function to reorder the dimensions if needed.
• If the dose map and the mask are in different coordinate systems, you may need to transform one of them to match the other. MATLAB provides various functions for coordinate transformations, such as imwarp or affine3d.

For further assistance please share more details on the issue you're facing currently.

you can also refer to the following documentation links for more information,

https://www.mathworks.com/help/images/ref/imwarp.html

https://www.mathworks.com/help/images/ref/affine2d.issimilarity.html

Hope this helps!