That's interesting and perhaps some doctor or nurse on board can tell us the answer.
The strong magnetic field can cause metal implants to dislodge, burn, and cause additional injuries. When you have any metal implant in your body, such as a pacemaker, prosthetic valves, or clips, you should let your radiologist or technologist know its brand name and model. If it is not confirmed to be compatible with the magnet, you should not take the MRI. If you have had bullet injuries or possible metal fragments in your body, X-rays can be taken instead for detection of metal objects.
Metallic implants/fragments that might be affected by magnet:
"That's interesting and perhaps some doctor or nurse on board can tell us the answer."
I am neither but I will tell you that I recently had an MRI of my left hand and wrist prior to surgery. I was laid on my side with my arm extended above my head. A lead shield was applied to my lower arm and sand bags to hold the hand and wrist in place. I didn't have to remove clothing with zippers or remove my partial plates. I guess it depends what area is being exposed to the ????? rays. I can only assume it would be the same for shrapnel, if he has any.
I'm am certainly not a Kerry fan. I'm not defending his claim. I just wanted to let those who have never had an MRI that it is possible as long as the metal is not being included in the exposure.
Rice shrapnel is probably not magnetic