Sure, the best way to do this is to get a DVI to HD-SDI converter, from either AJA or Black Magic Design or friends. This allows you to output using hardware acceleration from your GPU, but will be a valid rec 709 signal in professional HD land. You probably will want to verify this all on scopes, but thats the whole idea:

or DVI to HDMI, to HD-SDI:

good luck.

I should note for clarity the DVI extender can be used simply as a DVI to HD-SDI extender with a software switch, according to the docs.

awesome thanks for the tip! i have had success with blackmagic input cards running live feed for imag. excited to try.