Hyperpolarization (physics)
Encyclopedia
Hyperpolarization is the nuclear spin
polarization of a material far beyond thermal equilibrium
conditions. It is commonly applied to gases such as 129Xe
and 3He
which are then used, for instance, in hyperpolarized magnetic resonance imaging (MRI)
of the lungs.
Other methods for hyperpolarization include Dynamic Nuclear Polarisation
(DNP) for solid materials at cryogenic temperatures and para-hydrogen
used in chemical reactions in liquid solutions (PHIP).
DNP of nuclei like 13C
or 15N at typically ≈1 K can be coupled with subsequent rapid dissolution yielding a room temperature solution containing hyperpolarized nuclei. This liquid can be used in in vivo metabolic imaging for oncology and other applications. The 13C polarization level in the solid is reported as e.g. (64±5)% for a specific setup, and the losses during dissolution and transfer of the sample for actual NMR
or MRI measurements can be minimized to a few percent.
Spin (physics)
In quantum mechanics and particle physics, spin is a fundamental characteristic property of elementary particles, composite particles , and atomic nuclei.It is worth noting that the intrinsic property of subatomic particles called spin and discussed in this article, is related in some small ways,...
polarization of a material far beyond thermal equilibrium
Thermal equilibrium
Thermal equilibrium is a theoretical physical concept, used especially in theoretical texts, that means that all temperatures of interest are unchanging in time and uniform in space...
conditions. It is commonly applied to gases such as 129Xe
Isotopes of xenon
Naturally occurring xenon is made of nine stable isotopes. Xenon has the second highest number of stable isotopes. Only tin, with 10 stable isotopes, has more...
and 3He
Helium-3
Helium-3 is a light, non-radioactive isotope of helium with two protons and one neutron. It is rare on Earth, and is sought for use in nuclear fusion research...
which are then used, for instance, in hyperpolarized magnetic resonance imaging (MRI)
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
of the lungs.
Other methods for hyperpolarization include Dynamic Nuclear Polarisation
Dynamic nuclear polarisation
Dynamic nuclear polarization results from transferring spin polarization from electrons to nuclei, thereby aligning the nuclear spins to the extent that electron spins are aligned. Note that the alignment of electron spins at a given magnetic field and temperature is described by the Boltzmann...
(DNP) for solid materials at cryogenic temperatures and para-hydrogen
Spin isomers of hydrogen
Molecular hydrogen occurs in two isomeric forms, one with its two proton spins aligned parallel , the other with its two proton spins aligned antiparallel...
used in chemical reactions in liquid solutions (PHIP).
DNP of nuclei like 13C
Carbon-13
Carbon-13 is a natural, stable isotope of carbon and one of the environmental isotopes. It makes up about 1.1% of all natural carbon on Earth.- Detection by mass spectrometry :...
or 15N at typically ≈1 K can be coupled with subsequent rapid dissolution yielding a room temperature solution containing hyperpolarized nuclei. This liquid can be used in in vivo metabolic imaging for oncology and other applications. The 13C polarization level in the solid is reported as e.g. (64±5)% for a specific setup, and the losses during dissolution and transfer of the sample for actual NMR
Nuclear magnetic resonance
Nuclear magnetic resonance is a physical phenomenon in which magnetic nuclei in a magnetic field absorb and re-emit electromagnetic radiation...
or MRI measurements can be minimized to a few percent.