How to get 3d heat map model from pet-ct?
If you use a recent Slicer version then you can drag-and-drop the PET volume into a 3D view to see it rendered using volume rendering.
However, the image above looks like thr surface of the brain, which is not visible on PET images. Has the surface segmented from MRI (or maybe CT)? Are you sure the coloring comes from PET? Do you know how the PET volume is used for coloring the surface?