When younger, my daughter wore a medic alert bracelet when we traveled that indicated she was deaf-ASL ( small wrist, so couldn't get more descriptive than that ). I wasn't worried about flagging her as deaf inappropriately because she was never apart from us, but was worried about being separated in a car accident.
When she got her 2nd CI, we updated the bracelet to read NO MRI-CI and ASL below that. She's very upfront about either indicating when she can't hear and asking people to sign please at this age. So, I don't think she actually wore that one. Now, I'd like to place a GPS on her 
-- kidnapping scares the daylights out of me, especially when we're traveling.
I've spoken to several doctors about the MRI concern: will technicians know to watch for the CI if there's an accident. and they've explained that 1. They wouldn't be able to perform an MRI without parental permission and 2. In an accident they check for head injury, and especially with 2 CIs, you can feel them when you run your hands over her head and there are scars. I still worry about it, because I've had to explain to several doctors what a CI was--they just aren't all that well known, even in the medical community, and I don't know what's involved in training for MRI techs.
