Bazz8, what is the actual size of the mammography film that you use? I notice in your contact prints the black border you get is not the characteristic "broad T" shape imposed on standard sheet film exposed in standard sheet film holders.
For example I just measured a Fomapan 200 8x10 negative and got 198.5mm X 251mm; not actually 8x10 but still bearing the conventional rebate shadows on the long edges.