MIP - Max Intensity Projection with Bones

Development
1

Dear All, I am working on a project on visualizating MIP of carotid-cerebral arteries of two types, namely with bone shown and without. The results are like these.
QQ截图20221216145034
QQ截图20221216145046

Here, I succeeded in vislualization top image ( removing bones by a high intensity threshold and mip )

Class vtkFixedPointVolumeRayCastMapper

code are as the following

volumeMapper = vtk.vtkFixedPointVolumeRayCastMapper()
volumeMapper.SetInputConnection( vtkImage.GetOutputPort())
volumeMapper.SetBlendModeToMaximumIntensity()

But in order to get the second one, I used the same class on image (with bones), and only to get a bright silouette. Then I realized it is the intensity of bones that is shown in this mip image.
Later, I think I could achieve if by generating a No-Bones MIP, and on top of it, laying one slice of bone image (like image blending).
However, after searching quite a while, I could not make it.
Please help me if you know how to finish this blending process in VTK.
Any hint and suggestion is appreciated.
Thanks in Advance!!

2

Reply to myself,
I found that to get carotid-cerebral mip, it is not possible to get max intensity through whole image.
A thickness needed to choose before conducting mip.

3

Do you have two different datasets - with and without bones?

I recommend using vtkGPUVolumeRayCastMapper instead of the vtkFixedPointVolumeRayCastMapper. The mapper can also do an average intensity projection which might give you better results in the first case.

4

Dear Sankhesh,
Thank you for your reply.
I have one dataset (initially with bones)
Unfortunately, I dot not have GPU, I am afraid I cant use vtkGPUVolumeRayCastMapper.
I find that

vtkImageSlabReslice

might be the right function to do this job, and I found one example written in C++. Code will be like

vtkNew reslice;
reslice->SetInputConnection(reader->GetOutputPort());
reslice->SetOutputDimensionality(2);
reslice->SetResliceAxes(resliceAxes);
reslice->SetInterpolationModeToLinear();
reslice->SetSlabThickness(20);
reslice->SetBlendModeToMax();
reslice->Update();

I will try to convert it into python.
Thanks for your suggestion anyway.

5

Slab rendering can also be done with vtkImageResliceMapper. For an example of how to use, see TestResliceMapperSlab.cxx.

    vtkNew<vtkImageResliceMapper> imageMapper;
    imageMapper->SetInputConnection(reader->GetOutputPort());
    imageMapper->SetSlabTypeToMax();
    imageMapper->SetSlabThickness(20);
    imageMapper->SliceFacesCameraOn();

    vtkNew<vtkImageSlice> image;
    image->SetMapper(imageMapper);
    image->GetProperty()->SetInterpolationTypeToLinear();
    image->GetProperty()->SetColorWindow(2000);
    image->GetProperty()->SetColorLevel(1000);

    renderer->AddViewProp(image);
6

Dear David,
Thank you so much for your suggestion.
I will give it a try!!