How can I best manage Image Files in FrameMaker using TFS?

I am using FrameMaker 11 with Team Foundation Server 2010 and have a question about managing graphics.

We have several people working on the same book file (all in different locations).

Everything works very well except we kept running into issues with the graphic files.

We used to import all the graphics by reference, but it became difficult to manage the graphics outside of the frame files using TFS.

We have since copied the graphics into the Frame files which makes the file sizes very large.

I am wondering if anyone has experience with this and knows of a better way to manage the graphics.

Any info would be much appreciated.

Cheers,

Mack