I had an MRI cancelled because they didn’t know what I had inside my head. I’ve always been told just “PHIL glue” but for one MRI, they wouldn’t believe me. I was walked to the x-ray room to have a look for any coils etc but the radiologist there said that if something showed, they still wouldn’t know what they were made of, so I had to postpone until they had the report from the original hospital. You need to know what they are made of, even down to batch numbers, I believe.
I’d say that if you are not “MRI-safe” to get that added to your wristband (or, if you’ve taken up the Ben’s Friends Backpack scheme, get the relevant information onto your Backpack account).
See also Who’s going Backpack-ing with Ben’s?