Metal-free molecules improve MRI contrast in laboratory images

Kyushu University researchers developed water-soluble, metal-free molecules that emit deep-red light and improve contrast in magnetic resonance imaging. In test images, two versions produced approximately 2.5 to 4.5 times more MRI contrast than previously reported water-soluble molecules of the same type. The molecules could let researchers combine fluorescence imaging, which shows fine cellular detail, with MRI, which images deeper structures. One version fluoresced near cell nuclei for at least 24 hours in living-cell tests. The work remains an early demonstration: the researchers say animal studies are needed to assess whether the molecules are viable for further use.