How to Fuse image SPECT and CTA

Operating system: windows
Slicer version: 4.13
Expected behavior:
Actual behavior: anyone can help me with how to fuse image SPECT with CT Abdomen?

That is because my spect image inn 4D(one image), while my CTA has (3D images) have 673 frames.

how could I do?

Can you clarify what you mean by “4D (one image)” ? I’m not too familiar with SPECT but I thought it would be one volume.

Yes correct, one volume

In that case the regular overlay methods should work. The documentation is here:

https://slicer.readthedocs.io/en/latest/user_guide/user_interface.html#slice-view

Put the CT in the background and the SPECT in the foreground and then use the slider to adjust the opacity of the overlay. Someone probably has a video example somewhere but I’m not sure where.