BERKELEY, CA -- Researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley have developed a new technique for Magnetic Resonance Imaging (MRI) that allows detection of signals from molecules present at 10,000 times lower concentrations than conventional MRI techniques. Called HYPER-CEST, for hyperpolarized xenon chemical exchange saturation transfer, this new technique holds great promise for molecular imaging, in which the spatial distribution of specific molecules is detected within an organism. Ultimately, HYPER-CEST could become a valuable tool for medical diagnosis, including the early detection of cancer.
In a paper published in the October 20, 2006 issue of the journal Science, the team of researchers report on a technique in which xenon atoms that have been hyperpolarized with laser light to enhance their MRI signal, incorporated into a biosensor and linked to specific protein or ligand targets. These hyperpolarized xenon biosensors generate highly selective contrast at sites where they are bound, dramatically boosting the strength of the MRI signal and resulting in spatial images of the chosen molecular or cellular target.
This research was led by Alexander Pines and David Wemmer, who both hold joint appointments with Berkeley Lab and UC Berkeley. Their paper is entitled Molecular Imaging Using a Targeted Magnetic Resonance Hyperpolarized Biosensor. Co-authoring the paper with Pines and Wemmer were Leif Schrder and Thomas Lowery, plus Christian Hilty.
"Our HYPER-CEST molecular MRI technique makes optimum use of hyperpolarized xenon signals by creating a strong signal in regions where the biosensor is present, allowing for easy non-invasive determination of the target molecule," said Pines, one of the world's leading authorities on NMR/MRI technology, who holds a joint appointment as a chemist with Berkeley Lab's Materials Sciences Divis
Contact: Lynn Yarris
DOE/Lawrence Berkeley National Laboratory