Magnetic resonance imaging creates a useful, three-dimensional image of the body. To construct one, powerful magnets and radio waves measure the magnetic properties of water molecules in the body and cause them to emit signals that can then be mapped. Sometimes, however, those signals are weak. To enhance the images, radiologists often inject patients with metal-based substances, which can make the images easier to pick up but can also have side effects.

A new substance to assist with MRIs—synthetic, biocompatible nanodiamonds, like the one pictured above—might prove friendlier to the body. Unlike metal-based agents, a diamond is chemically stable and doesn’t break down or combine in harmful ways with other chemicals. A research team has recently discovered a way to manipulate the magnetic properties of these tiny diamonds, ranging from 18 to 125 nanometers, that helps them produce a stronger signal. “Our idea was to exploit the unusual properties of nanodiamonds and turn them into a molecular imaging agent,” says Matthew Rosen, a physicist at the Athinoula A. Martinos Center for Biomedical Imaging at Massachusetts General Hospital and senior author of a recent paper about nanodiamonds in Nature Communications.

Rosen and his team boosted the magnetic signal of the diamonds through a process called hyperpolarization, which lends them a magnetic profile that lights up in an MRI. “Using this technique would allow you to track where and how the nanodiamonds disperse throughout the body,” says Rosen, although he notes that the team has so far only tested the efficacy of their approach using aqueous diamond solutions in vials.

In the future, researchers might combine such tiny diamonds with molecules that target tumors, allowing MRIs to show the progression of cancer inside the body. The diamonds might also be mixed with drug compounds, to see how and where they travel. “Nanodiamonds have the potential to revolutionize the field of molecular imaging,” says Rosen. “They can be used for tracking drugs or diseases, or any process you want to noninvasively study and image, especially on a cellular and subcellular level.”