Display many MRI slices in one window

Question

Is it possible to display all MRI images side by side in one VTK , or maybe even QT window? So far I've got all MRI slices from reconstruction in a matrix vector and I can scroll them (write in c++). I don't know if I can put all these images in one window and display them. Below I enclose example image with what i want to achieve. Thanks for any response.

MRI Slices

score 1 · Answer 1 · answered Jan 24 '18 at 23:05

In order to achieve what you want, you can divide it as a series of sequential steps:

First, you need to scan and read MRI dicom files, which can be done through vtkDICOMDirectory and vtkDICOMReader.
Assuming you have an MRI volume, you can extract each slice through vtkExtractVOI, and map this information to a vtkImageActor, which you can add to a renderer. In turn, you need to set the viewport on the renderer, so that you can display images side by side, as you want.

Here is a small example, please adapt it to your needs:

//Use vtkDICOMDirectory to scan a directory with MRI images
vtkSmartPointer<vtkDICOMDirectory> dicomDir = vtkSmartPointer<vtkDICOMDirectory>::New();
dicomDir->SetDirectoryName("**Insert the path to your images here**");
dicomDir->RequirePixelDataOn();
dicomDir->Update();

int n = dicomDir->GetNumberOfSeries();

vtkSmartPointer<vtkDICOMReader> reader = vtkSmartPointer<vtkDICOMReader>::New();

if (n > 0){
    //Read the first series found (just for example)
    reader->SetFileNames(dicomDir->GetFileNamesForSeries(0));
    reader->Update();

    //Get the extent
    vtkImageData* mriVolume = reader->GetOutput();
    mriVolume->GetExtent(mriExtent);
    xmin = mriExtent[0];
    xmax = mriExtent[1];
    ymin = mriExtent[2];
    ymax = mriExtent[3];
    zmin = mriExtent[4];
    zmax = mriExtent[5];

    //Extract a slice of interest
    vtkSmartPointer<vtkExtractVOI> extractSlice = vtkSmartPointer<vtkExtractVOI>::New();
    extractSlice->SetInputData(mriVolume);

    // Define viewport ranges (Adapt here to it covers your entire range of slices. Here we only create 4 viewports, so 4 images in total)
    double xmins[4] = {0,.5,0,.5};
    double xmaxs[4] = {0.5,1,0.5,1};
    double ymins[4] = {0,0,.5,.5};
    double ymaxs[4]= {0.5,0.5,1,1};

    vtkImageData* slice;

    for(unsigned i = 0; i < 4; i++){
        extractSlice->SetVOI(xmin,xmax,ymin,ymax,i,i);
        extractSlice->Update();

        //Get the image data
        slice = extractSlice->GetOutput();

        //Image Actor
        vtkSmartPointer<vtkImageActor> imageActor = vtkSmartPointer<vtkImageActor>::New();
        imageActor->GetMapper()->SetInputData(slice);

        //Add a renderer
        vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
        renderer->SetViewport(xmins[i],ymins[i],xmaxs[i],ymaxs[i]);
        renderer->AddActor(imageActor);
        renderer->ResetCamera();

        //QT+VTK connection (assumes you have a QVTKWidget named mriWidget)
        ui->mriWidget->GetRenderWindow()->AddRenderer(renderer);
        ui->mriWidget->GetRenderWindow()->Render();
    }
} else {
    std::cerr << "No DICOM images in directory!" << std::endl;
}

References:

Display many MRI slices in one window

1 Answers1