Could Gas-Based Contrast Agents Replace GBCAs?

Researchers from the Leibniz Institute for Molecular Pharmacology (FMP) in Berlin and the California Institute of Technology are creating hyperpolarized xenon gas-based contrast agents that will improve the sensitivity of magnetic resonance imaging (MRI), according to a study published in ACS Nano.

The gas-based contrast agents, or “gas vesicles”, aim to solve the problems presented by traditional gadolinium-based contrast agents (GBCAs). GBCAs lack sensitivity and often demand high quantities, which can pose health risks. They’re generated by specific bacteria, and behave similarly to a fish’s swim bladder, which enables the bacteria to balance their buoyancy while in water. Their adaptability can accommodate a range of hyperpolarized xenon gas quantities.

When a patient inhales xenon gas, it’s dissolved into their bloodstream and will piece off into vesicles. MRI image quality and sensitivity is improved since significantly more xenon enters the gas vesicles than GBCAs.

“The protein structures have a porous wall structure through which xenon can flow in and out. Unlike conventional contrast media, the gas vesicles always absorb a fixed portion of the xenon that is provided by the environment,” said Leif Schröder, PhD, from FMP. The vesicles are able to absorb more xenon and according to PhysicsWorld, “MRI can take advantage of this accumulation and subsequent absorption.”