MRI grade vs Hospital grade electric outlets

I know both have been suggested as an upgrade to the run of the mill cheap outlets. I also know there may be "even better" outlets.   I know the MRI grade has non magnetic metal components. Bottom line, does it make a difference one can hear? I have about 1/2 dozen Hubbell 30 Watt hospital grade outlets. Got them fairly inexpensively. Are the MRI grade worth the extra $$$?