The Freaky, Clanking, Buzzing, Whirring Glory Of MRI

September 22, 2016

There are a lot of ways the most detailed, abstract and sophisticated kinds of science show up in our daily lives.

In a nation that sometimes forgets the power and promise of its own scientific endeavor, it’s good to be reminded of that link — as I was this week when I went in for an MRI on my shoulder.

MRI stands for magnetic resonance imaging. Really, though, the process is called NMRI with the N standing for nuclear. The medical field has dropped the “nuclear” part because it freaks a lot of people out. I could get all snarky about that, but I won’t because I can now see how getting an MRI might be a bit freaky for some folks. Someone slides you into something of a tube. Then you have to lie still for a bit while the enormous machine you’re surrounded by makes a whole lot of noise.

But the coolness factor totally overwhelms everything else.

During an MRI, all the spinning protons inside the hydrogen atoms inside the water molecules inside your body get flipped this way and that. The outcome of this magnetically controlled proton spin-flipping is a super high-resolution view inside your skin.

From spinning protons to pictures of your innards, that is pretty amazing.

The whole thing works because, years ago, someone invented quantum physics — which is this crazy abstract theory about how atoms and subatomic particles work. And before that, someone else invented electromagnetic theory, which describes how the flow of electric currents generate radiation (i.e. light of different wavelengths). There was also a huge amount of other stuff really hardworking and creative folks had to dream up. All of it fit together in just the right way so we could see the goop inside our bodies (including my messed up shoulder).

Since seeing what’s going on is the first step to fixing what’s going on, the MRI has proved to be something of a miracle in the domains of healing. The key point today is that this miracle rests on a simultaneously broad and deep understanding of how nature works. It’s so broad and deep that few people could really trace the full path from basic physics theory all the way up to biological/health diagnostics. And yet we all rely on these machines when we need them. We rely on the experts who design, build and run them.

That’s why the MRI — in all its freaky, clanking, buzzing, whirring glory — is just one more example of the power of science in all of our lives.

Here, here and here are a few videos that explain the basic physics of NMRI. Each has its strengths and weaknesses. I would watch them in order.

Adam Frank is a co-founder of the 13.7 blog, an astrophysics professor at the University of Rochester, a book author and a self-described “evangelist of science.” You can keep up with more of what Adam is thinking on Facebook and Twitter: @adamfrank4

Copyright 2016 NPR. To see more, visit