I think the point is we can afford massive machines for the TSA that are essentially paid for by the Federal Budget, and used by millions each day for free, but we can't do the same for MRI machines.
Not really relevant, just makes the whole thing worse imho. There are new carryon bag scanners which are basically CT scans I think. Again not really relevant just makes it all worse. We could afford better medical care but we spending it on security theater and power tripping.
My point is that there's not actually any useful connection between the TSA scanners and medical scanners, it's comparing apples to oranges. By all means be angry about the lack of healthcare in the US, by all means blame other spending, but singling out the TSA is arbitrary.
Granted, I imagine an MRI scan still takes longer than 30 airport scans.
Interestingly the price of the body scanners and a typical MRI are in the same ballpark, from my experience and what I could glean online.