Edwin Versteeg

The heart beats irregularly. Standard MRI pretends all beats are the same: it stacks them on top of each other, like a photographer shooting a dancer with a long exposure. The result is a blurry smudge — pretty, but useless if you need to see each individual movement. The new approach films the heart like a video: frame by frame, with no gaps.

A flashlight spreads light in a broad beam, while a laser cuts a narrow path and picks out the finest details. In magnetic resonance imaging (MRI), the gradient, a rapid change in the magnetic field along the body, plays the role of that laser.