Not going to trust "newaccount74" with that info. It seems that the experts say that if the metal in the body is attached to bone (a screw or a plate), that is okay, but not if the metal is not permanently fastened to bone, so "surrounding tissue" is not going to stop the metal from causing problems.
>MRIs don't accelerate objects instantaneously.
See some of the videos below for evidence to the contrary. Large metal objects inside the room can definitely accelerate very rapidly and suddenly, and unexpectedly and has killed people.
https://www.youtube.com/shorts/2NNJrOsw8vs "Metal objects not attached to bone may not be safe"
https://www.youtube.com/watch?v=naAZVCxhEcI
https://www.youtube.com/watch?v=uDfwxoigZZk
https://www.youtube.com/watch?v=5KuzTyn45og