New MRI Dye Enables Drastically Higher Resolution 3D Images of Living Brain

In a breakthrough that can drastically increase the resolution and detail of magnetic resonance imaging, a fluorescent dye that enables high-resolution (about 1 micron) 3D images of the cerebral vascular system has been synthesized by researchers at the Laboratoire de Chimie (CNRS) in France.

In collaboration with the Institut des Neurosciences of the Université Joseph Fourier in Grenoble, France, the researchers developed the "Lem-PHEA chromophore" dye that exhibits exceptionally high fluorescence in the near-infrared region of the biological transparency window and can also pass through the skin. It features solubility in biological media, low cost, non-toxicity, and full elimination by the kidneys, suggesting that it may be suitable for in vivo imaging, the researchers say.

By injecting the dye into the blood vessels of a mouse, the scientists could reveal details of the rodent's vascular system with previously unattainable precision -- compared to current dyes (such as Rhodamine-B and cyanine derivatives), and to conventional MRI medical imaging, which is limited to resolution of a few millimeters -- increasing the resolution by a factor of 1000.

References:

Julien Massin et al., A water soluble probe with near infra-red two-photon absorption and polarity-induced fluorescence for cerebral vascular imaging, Chemical Science, 2013, DOI: 10.1039/C3SC22325F