MRI machines cost $2-5 million. Good luck paying for them, along with the expertise needed to analyze them, at $100-300 a pop. There's a reason why the waiting lists for MRI's and other expensive imaging/diagnostic tests are much longer outside of the US (like 1-2 days versus 1-2 months for non-emergencies) - because providers can't afford to procure more equipment or hire more physicians due to the artificially low price of compensation for such services set by the government.
A single state in the US has more MRI machines than all of Canada, and we have nearly 5x as many per million people. There's a reason for that, and it isn't simply because we get to charge more for it here.
The superficial and biased analysis re: healthcare in the US on this forum is amusing. This is an incredibly complex, multifaceted issue. Reciting platitudes and acting like a single payer system is a panacea is a joke. That said, I am not a proponent of the extant system, nor of completely free market healthcare, which would be disastrous for a number of reasons.