How would a transponder function under such conditions?
There have been studies conducted regarding the effects of a magnetic resonance imaging (MRI) procedure on RFID tags, but I have never seen any tests studying how a transponder would work during the procedure, when it would be exposed to magnetic induction equal to 7 Teslas. Since passive HF and LF use electromagnetic induction to power tags, it is possible that the tags would not function at all. Magnetic induction typically doesn't affect radio waves, so a passive UHF transponder might work, but I am not an RF engineer so I cannot say for sure. If any RF engineers are able to provide a more educated response, they are welcome to do so below.
—Mark Roberti, Founder and Editor, RFID Journal