> Of course, there may not be a meaningfully-competitive local market, so patients may end up needing to go to the physician-owned imaging facility.

Certificates of Need. A legal requirement in most states for creating a new healthcare facility. Ostensibly to make sure that the population in that area has adequate healthcare options. But lobbied for by healthcare facility and hospital owners, it actually surveys other providers (your competitors) in the area and asks if their revenue would be adversely affected by you opening up. Too much of this, and no CoN for you.