fusion of different sequencies and segmentation mask after editing in one study dicom extension

Operating system: windows
Slicer version:
Expected behavior:
Actual behavior:

This should be easy to do in recent Slicer Preview Releases, using Segment Editor module. You can change the master volume anytime. You can also copy/move segments between segmentations in Segmentations module.

If you need to spatially align images or segmentations then you can use one of the many registration methods available in Slicer.