I guess steel bridgework and pins or screws in your bones are a no-go, then?
I am carrying a fair amount of steel in my lower body (ex-motorcycle road racer).
I have had several MRIs with the steel in place.
The technicians take great care to make sure NOT to do the MRI on the actual body part with the steel in it (i.e. I go in head first and they do not let my legs actually go into the machine). But, I THINK the fact that everything is stainless steel (non-magnetic) provides a fair level of protection.
IN any case, I have never had a plate or screw come flying out through my flesh.
If they have been in for more than a couple of mos the are OK, but they will degrade the image. The worry about metal is something small (ie fragment) that will move to somwhere that it can cause big trouble
For example, welders should not have MRIs - there is a high liklihood of fragments of metal in the eyes that could shift and cause problems with visions. And of course, pacemakers are big no no’s