From Looking Glass Universe.

How do MRIs work? It turns out that MRIs measure the quantum spin of your protons, and use that information to make a super detailed 3D map of your body.

This video is from the series "Quantum experiments at home": https://www.youtube.com/playlist?list=PLg-OiIIbfPj3mDFx5zjVPtgiGwZMM4Erw