If you capture those maps in a .wmf or .bmp format, netViz can import them as backgrounds to create a template for you to begin your netViz diagrams. A better approach may be to use the backend database of your NMS to create instances of the objects in the map in your netViz project.
How to import Topology maps into netViz using .wmf or.bmp formats
Can netViz import topology maps generated by OpenView, Tivoli or other Network Management Systems
netViz Enterprise Server
(Legacy KB ID CNC TS14879 )