Improving MRI

Researchers at

, the

, the

and the

in

have created a new class of magnetic resonance imaging (MRI) contrast agents that are at least 40 times more effective than the best in clinical use.

The new agents, called gadonanotubes, use the same highly toxic metal, gadolinium, that is given to more than a quarter of MRI patients today, but the metal atoms are encased inside a carbon nanotube. Shrouding the toxic metals inside the benign carbon is expected to significantly reduce or eliminate the metal's toxicity.

"In prior work, we have boosted the effectiveness of gadolinium MRI contrast agents by encasing them in spheres of carbon called buckyballs," said Lon Wilson, professor of chemistry at Rice. "Each nanotube will hold more gadolinium atoms than a buckyball, so we expected them to be more effective agents. But they are actually much, much better than we anticipated, so much so that no existing theory can explain how they work."