Xin Zhou Develops Novel Molecular Imaging Methodology

A Berkeley radiologist describes his "Hyper-SAGE" technique in PNAS.

Xin Zhou, an MRI radiologist in the lab of chemist and leading MRI technologist Alexander Pines at the University of California, Berkeley, made headlines in October for his work developing a novel NMR/MRI methodology for molecular imaging. Zhou’s invention, which he says enables early stage detection of cancer tumors, is described in a paper in the Proceedings of the National Academy of Sciences, "Hyperpolarized xenon NMR and MRI signal amplification by gas extraction." The technique, dubbed Hyper-SAGE, has the potential to detect ultra low concentrations of clinical targets, such as lung and other cancers. The key is xenon gas that has been zapped with laser light to “hyperpolarize” the spins of its atomic nuclei so that most are pointing in the same direction.

“Hyper-SAGE is a totally novel way to amplify a solvated xenon MRI/NMR signal in that instead of a chemical process, which is what previous signal enhancement techniques relied upon, it is a physical process,” says Zhou. “Because gas can be physically compressed, the density of information-carrying polarized gas in our detection chamber can be much greater than the density of an information-carrying solution. This means we can detect MRI signals from concentrations of molecules many thousands of times smaller than can be detected with conventional MRI.”