Maybe for working directly on MRI's, but mostly the recent ones are a little easier to work around. There are different strengths that have diffrrent requirements.
15 yrs ago they had to be in their own room, with thick concrete walls and an entrance that had a 90 degree turn, or two. We piped copper pipe to the fire sprinklers. Then the concrete went away, but the walls were lead lined to 8'-0" AFF. Now they are everywhere with nothing more than distance and sheetrock..
My experience is from designing fire sprinklers for various magnetic type machines, including an NMR. It was one of 6 when installed, cost 8 million for the machine only, and the gauss field was so big that they had to design a bump in the exterior buildings brick wall to accomodate it. The only one we had to use magnetic tools around www the NMR. It the room it was in took 2 floor levels. Tha part where you put whatever you were imaging in was about 1 cubic foot. Supposedly, if a ferrous tool stuck to this machine, it could hold you stuck between it and it would cost 10 grand to turn it off to get the errant tool off tge NMR.
That bulge in the exterior bricks was only on the first floor of a 12 story building. They didn't want anyone walking through the gauss field.
Chilly
Because I can't feel I have to get x-rays and MRI's a lot. (If I get bruised and don't know how it got there, for instance.
There have been a lot of improvements to MRI machines. The last MRI I had was last month in November. It was on my right hand so I had to go into the tunnel to a point just below my shoulders. This time I could leave my belt, with a small metal loop buckle, on.
