Yes and no on the PE's role ; PE is in the end a financial institution interested in extracting every cent possible, not to deliver the best healthcare possible. PE groups go in without the intention of running it, but juicing the books in order to flip it for a quick 20%+ profit margin. They absolutely no nothing about running any sort of practice nor do they want to, and often leave the physicians in charge initially - which is why you may have seen some stakeholders claim there's no change to how they practice things...at first. The squeeze occurs after the second sale or if it doesn't happen, if the latter happens then the PE firm tries to at least show some cash flow out of it.
For radiology since there's really not much you can "optimize" other than "efficiency" and we all know how that goes at a certain point. My layperson opinion is that once interest rates come down a bit more, you may see the final flip, and that's when things will get bad (like in House of God, they can always hurt you more). PE firms have also learned their lessons from the 1990s and have these punishing reward structures to keep people locked in (one example is you get your bonus spread out over 5 years, and/or the practice has to grow to X number of physicians). I know it sounds doom and gloomy but I think in the next few years we are going to see a smash grab and run on Medicare/insurance which is going to leave lingering effects for a while.