Physics,
One of my favorite quotes of my Late great Neighbor Richard Feynman:
"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled"
DD is limiting the possibility that mother nature rears up and kicks you in your butt.I think thats what happen here. The cold reality of how long and how much money this will cost is now creeping into the market and PPS though still pretty high for what we know.
BTW If DVIS works and is truly an amazing product then we should be hitting up every medical journal and famed radiologist on the planet.