hiperpolarizációját

Hyperpolarization is a phenomenon in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) that significantly increases the sensitivity of these techniques. Normally, the nuclear spins of atoms align either with or against an external magnetic field. This alignment creates a slight population difference between the two states, which is responsible for the NMR signal. Hyperpolarization artificially enhances this population difference, leading to a much stronger signal.

There are several methods for achieving hyperpolarization, including Dynamic Nuclear Polarization (DNP) and spin-exchange optical pumping (SEOP). DNP typically involves using unpaired electrons to transfer their high polarization to nuclear spins at low temperatures. SEOP uses circularly polarized laser light to polarize alkali metal atoms, which then transfer this polarization to other nuclei through collisions.

The increased signal strength from hyperpolarized samples allows for faster data acquisition or the study of systems at much lower concentrations than would otherwise be possible. This has opened up new applications in various fields, including medical imaging, where it enables real-time metabolic imaging, and chemical analysis, allowing for the detection of trace amounts of specific molecules. The injected hyperpolarized agents are typically short-lived, meaning their signal decays over time due to relaxation processes.