How Research on Diamonds Could Improve MRIs
The paper, authored by postdoctoral researchers Jacob Henshaw and Daniela Pagliero, Professor Carlos Meriles of CCNY and The Graduate Center, and previous postdoctoral researcher Pablo Zengara, appears in the journal PNAS.
Technologies like MRI machines in hospitals rely on “spin”—a property of subatomic particles and nuclei. Much like tiny compasses, these spins tend to align in the presence of a magnetic field. Polarization is a measure of how well the spins are aligned with the field. In an MRI scan, the strength of the signal depends on polarization.
The problem, Meriles said, is that “even for the strongest magnets you can imagine building today, this polarization is really very small.”
To fix this, the researchers are looking to diamonds. Specifically, they’re looking at a type of defect in diamonds called NV centers. These defects have a special property, Meriles said. If you shine green light on them, their spins will polarize to almost 100%.
The researchers want to pass this near-perfect polarization from the diamond to another material. If you could transfer that polarization to water, for example, you could then inject hyperpolarized water into a patient receiving an MRI to get a clearer image. Today, MRI technicians sometimes use gadolinium contrast agents, which can cause adverse reactions in certain patients.
But there are other defects in diamonds which prevent a polarization transfer. In this proof-of-principle paper, the researchers demonstrate a way to avoid fighting these defects, and instead use them to help make the transfer.
This “spin-pumping” technique could someday benefit not only MRI technology, but also spectroscopy methods that researchers and pharmaceutical companies use to glean information about molecules.