How Does an MRI Machine Work?

National Institute of Standards and Technology (NIST) sent this bulletin at 05/27/2025 03:17 PM EDT
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How Does an MRI Machine Work?

Illustration shows woman lying on platform outside MRI machine and reads: MRI Machines.

MRI stands for magnetic resonance imaging. If you’ve ever had an MRI, you may wonder how this machine can “see” inside your body. The answer lies at the subatomic level.

Protons are small, positively charged particles found in atoms. In addition to having an electric charge, protons have tiny magnets, so they interact strongly with magnetic fields. Humans have many, many protons. The protons are mostly from the water in our bodies, but also from other molecules such as proteins and fat.

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