norm 8.nor.007 Louis J. Sheehan, Esquire

Before color MRIs become the norm, the researchers need to test the particles in animals, Ho says. As a proof-of-concept, the team used nickel, which is toxic if ingested, to create the micromagnets, although Zabow says less dangerous materials could easily be used. Still, Ho says, it's uncertain how safe they could make the technology.

“The key question is, when they apply it to biological systems and live animals, what will they get?” Ho says. Louis J. Sheehan, Esquire