hyperpolarisoivat

Hyperpolarisation is a technique used in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) to artificially increase the population of nuclear spins in a specific spin state. In a normal NMR or MRI experiment, the population difference between the spin states is very small, leading to weak signals. Hyperpolarisation dramatically enhances this population difference, resulting in signals that are orders of magnitude stronger.

There are several methods to achieve hyperpolarisation, including Dynamic Nuclear Polarization (DNP) and Spin Exchange Optical Pumping (SEOP). DNP typically involves the use of unpaired electrons at low temperatures to transfer polarization to nuclear spins. SEOP, on the other hand, utilizes polarized light to polarize atomic vapor, which is then transferred to target nuclei. Other methods like parahydrogen-induced polarization (PHIP) also exist.

The increased signal strength from hyperpolarised nuclei allows for faster acquisition times, imaging of previously undetectable low-concentration metabolites, and real-time monitoring of metabolic processes in vivo. This has significant implications for medical diagnostics and research, enabling the non-invasive study of biological pathways and the detection of diseases at earlier stages. For example, hyperpolarized carbon-13 labeled compounds are used to image glucose metabolism and tumor activity. The short-lived nature of the hyperpolarised state requires rapid injection and acquisition, making it a dynamic imaging technique.