Exactly! Maybe my initial comment should have emphasized the relative significance of reasons for preferring X-ray CT over MRI in an emergency: 1) Speed. 2) D

Exactly! Maybe my initial comment should have emphasized the relative significance of reasons for preferring X-ray CT over MRI in an emergency: 1) Speed. 2) Depiction of bone (less relevant if it's not a trauma case with suspected broken bones). ?) Risk to patient in case of internal metal. Some MRI suites are set up with airport style metal detectors to prevent people from accidentally bringing metal into the magnet room. I haven't heard of metal detectors being used to screen non-responsive patients, though. It's a reasonable question, but I think that even if some instantaneous metal detector with a false negative rate of 0 could be made, emergency docs would rather scan for five seconds to get a CT than five minutes to get an MRI that has coarser resolution, poor bone depiction, and a chance that the whole image is ruined if the patient moves.