Can the Studio XPS 435MT graphics card be up-graded form its existing ATI 3450 card?

Can the Studio XPS 435MT graphics card be up-graded form its existing ATI 3450 card?

I'm not sure it can with this particular model? I know they come with much stronger graphic cards though. Which only leads me to the conclusion it is possible to do so.

I hear stories that the 435MT doesn't have any room that will enable an upgrade pertaining to the graphics card?

If it is possible to upgrade the system with a better graphics card, what is the best card this system (435MT) will allow (brand and size)?

Thanks

R.W.