They have extensive screening and education and safeguard procedures, for the patients. I'm guessing hubby skipped (probably wasn't even offered) all those and just dashed in the door when called. Tech still should have put hubby through "the talk" if he was anywhere close to the door to the room.

MRI is one of the most sci-fi come to life technologies most people are likely to encounter in their lives. Superconducting magnets are about as non-intuitive as it gets, once they get you past the point of your ability to resist the force, there's no recovery - you're going faster and faster until the metal hits the housing. There have been multiple accidents with steel oxygen cylinders - for the obvious reason: they're so common in the environment where MRIs are used, and it's no small feat to get the cylinder removed.