[ska]

That is not true. It doesn’t involve ionizing radiation, so not a dose risk like CT. But look up PNS and SAR (peripheral nerve stimulation and specific absorption rate), for example. This is mostly handled well for standard pulse sequences of course, but not “zero risk”.

Beyond that, there is a reliance that you do not have any implants etc., even some tattoos. And you tell the truth about it. From the clinics point of view too risky.

[mattkrause]

I don't think that's what they're especially worried about; those are fairly minor.

Instead, think about interacting with someone who a) is so convinced that they need an exploratory MRI but b) can't convince a doctor of that need. I'd be afraid that either I'll be stuck dealing with someone perseverating over a totally normal anatomical variation (and everyone has a few). If they get sick later, I might also get dragged into a debate over whether I should have noticed something on that scan, done a different scan, or whatever, possibly with big legal implications.

This is why our techs will happily scan a fruit or something, but don't run an ad-hoc clinic.

[ska]

I agree that in the parent comment case, there is no reason to risk a review or lawsuit which is probably mainly why a clinician wouldn't do it; I alluded that that in another comment.

This one was specifically a comment about "zero risk" on MRI, it's not true. Low risk, sure. But people have been hurt.

I also suspect any clinician is going to look askance at a low risk action that isn't necessary, but the potential liability is the kicker here.

[mattkrause]

It's pretty close.

Nothing is totally risk free, but compared to most medical procedures--and most activities of daily living--MRIs are a walk in the park. For a subject with no implanted devices, I would bet the drive to the scan center is much more dangerous. I just flipped through MAUDE (https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/d...) and I couldn't find any adverse events that were more severe than a small burn or blister.

[ska]

Agree it's low risk, I was being pedantic.

There have been deaths of course, also, but not due to normal operation.