Hi all, is there anyone known multi-modal medical image fusion project,like CT/PET, CT/MRI and so on?

Now I want to reseach the multi-modal medical image fusion, i want to find an open source project as first.

There is SlicerPET (blog post, git repository). Its main point is biopsy navigation, not fusion. But it is an open source project which also does PET/CT fusion, so you can take a look at it.