Of course you don't want to ignore that alarm 200 times a day. That's why I'd rather just ban everything with metal. All of these things have non-metal alternatives that you could easily enforce in such a specialized setting. Why wouldn't you, if it can save lives?

That's a very easy fix. Just make the volume proportional to the amount of metal detected.

And the 10+ a day with a knee joint or a hip joint replacement?

And then what if they also have a pacemaker or aneurysm clip?

An unsafe clip is tiny, and it will kill them. You can’t depend on a metal detector.

Technology might help, but people following process is what safety depends on.

If staff follow the rules the MR suite is very safe.

https://mrisafety.com/

What does this mean? I thought you can't get close with any ferrous metal whatsoever. If it beeps, you're not allowed in. It's not like in an airport where "oh it's just a coin".

No, you can.

Belts, buckles, bra etc are fine on staff.

A coin is a problem. Hip or knee joint replacement and various screws and plates are fine (some contain some iron).

Like all bad answers, the answer as to whether it’s ok in the scan room is ‘it depends’.

Metal detectors can detect nonferrous metals too.