vtkSmartPointer<vtkImageMapToWindowLevelColors> mOverlayMapper;
vtkSmartPointer<vvBlendImageActor> mOverlayActor;
vtkSmartPointer<vtkImageReslice> mFusionReslice;
vtkSmartPointer<vtkImageMapToWindowLevelColors> mOverlayMapper;
vtkSmartPointer<vvBlendImageActor> mOverlayActor;
vtkSmartPointer<vtkImageReslice> mFusionReslice;