The chamber of an MRI machine is a surreal environment. You’re flat on a slab and fed into a tube. Inside, it’s dark and noisy, intermittent reverberating around your head.

I’ve always attributed this chaotic banging to atoms ricocheting, doing quantum stuff, rendering the invisible visible. Bones, organs, blood vessels exposed. Dodgy cell clusters held up to the light for a radiologist’s inspection.

MRI is short for “magnetic resonance imaging,” so presumably magnets are involved. I don’t know how. I’m not a scientist.

I do know I find getting an MRI an existentially jarring experience. Before the technician loads you into the machine, you are —an individual with ideas and plans and memories; inside the machine, you are a body. I don’t like MRIs.

And yet, on a gray day last December, I find myself at the clinic on 34th Street in New York City, a stone’s throw from the Penn Station train that will soon whisk me upstate, getting scanned head to toe for the hell of it. Because I want to peer into the black box of my body. Because I want to live.

Prenuvo is the best known among a generation of biotech start-ups offering preventive whole-body scans. Its promise is that, by voluntarily submitting yourself to an MRI every year or so, you’ll be able to keep tabs on your health and catch maladies early, when they’re easy to treat or, better yet, reversible via lifestyle changes. This sounds so terribly logical—who wouldn’t rather discover a malignant tum.