When I did anesthesia for MRI we had aluminum O2 tanks. Our Anesthesia machine was designed for MRI machine use. You have to get fairly close to the MRI machine with magnetic material to have a problem. Once you cross that point the magnetic object is buried in the machine. There are you tube vidios of people placing metal objects into MRI machines. They can be pretty entertaining. MRI machines can also “quench”. The electromagnets are cooled by liquid nitrogen. If the cooling apparatus fails the MRI machine will release nitrogen in a rather dramatic fashion. MRI rooms have O2 monitors so if a nitrogen leak reduces O2 levels the staff will be earned. Look up metal objects MRI and MRI quenching.
I’ve worked med devices for about 18 years now (manufacturing, supply chain, etc). 12 of it was for GE mainly in MRIs
The stories I’ve heard about inadvertent quenchings, metal taken in the room, etc
Then there was a guy - I think in Brazil - that disabled an auto shutoff to run some test scans - left the place unattended and the body coil overheated to the point the epoxy caught fire. Lost the whole suite - managed to save the rest of the building though.
Here’s a veterinary version that didn’t have a proper setup for Helium boil off, over-pressurized, and exploded: http://www.dailymail.co.uk/news/article-2983440/One-man-fighting-life-two-injured-MRI-machine-exploion-New-Jersey-animal-hospital.html
There was one in India where they found the emergency quench wasn’t even wired.
Between the cryogens, magnetic field, high voltage, and potential pressures the things can be very dangerous if not installed, maintained, and operated properly.