I am a medical physicist. I know how the MRI works. The goal of the MRI machine is to make the patient's body emit radio waves, which are then measured. Obviou

I am a medical physicist. I know how the MRI works. The goal of the MRI machine is to make the patient's body emit radio waves, which are then measured. Obviously there is some RF going on! (This corresponds to a spatial Fourier transform etc.) And while it might not seem "often" to you, it's worth considering that the RF levels in the room are enough that we care about tissue heating and sparks on nonmagnetic conductors. This is many thousands of times stronger than a TV signal. There are many cases where the patients require "assistance", which is used in roughly the same sense that cats require assistance in taking a shower. Then there are spectrometrists and so forth — not every MRI is like the one you get as an outpatient with a broken leg.