English
Related papers

Related papers: MRI of the lung using hyperpolarized He-3 at very …

200 papers

We present NMR measurements of the diffusion of hyperpolarized helium-3 in the human lung performed at fields much lower than those of conventional MRI scanners. The measurements were made on standing subjects using homebuilt apparatus…

The human lung and its functions are extremely sensitive to gravity, however the conventional high-field magnets used for most laser-polarized 3He MRI of the human lung restrict subjects to lying horizontally. Imaging of human lungs using…

The main findings of the european PHIL project (Polarised Helium to Image the Lung) are reported. State of the art optical pumping techniques for polarising ^3He gas are described. MRI methodological improvements allow dynamical ventilation…

Medical Physics · Physics 2016-08-16 Michèle Leduc , Pierre-Jean Nacher

The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation.…

Medical Physics · Physics 2007-07-25 L. L. Tsai , R. W. Mair , C. -H. Li , M. S. Rosen , S. Patz , R. L. Walsworth

Cross-sectional imaging of the lungs, or pulmonary imaging, has proven to be an incredibly valuable tool in a wide range of pulmonary diseases. The vast majority of lung imaging is done with CT, as it is fast enough to freeze respiratory…

Medical Physics · Physics 2024-02-27 Peder E. Z. Larson

Through inhalation of, e.g., hyperpolarized $^3$He, it is possible to acquire gas diffusion magnetic resonance measurements that depend on the local geometry in the vast network of microscopic airways that form the respiratory zone of the…

Biological Physics · Physics 2021-05-28 Niels Buhl

After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low…

Instrumentation and Detectors · Physics 2015-06-15 G. Collier , T. Pałasz , A. Wojna , B. Głowacz , M. Suchanek , Z. Olejniczak , T. Dohnalik

We perform metastability exchange optical pumping of helium-3 in a strong magnetic field of 1.5 T. The achieved nuclear polarization, from 80% at 1.33 mbar to 25% at 67 mbar, shows a substantial improvement at high pressures with respect to…

Atomic Physics · Physics 2009-09-29 Marie Abboud , Alice Sinatra , Xavier Maitre , Genevieve Tastevin , Pierre-Jean Nacher

This article reviews the physics and technology of producing large quantities of highly spin-polarized, or hyperpolarized, $^3$He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping, and surveys applications…

Atomic Physics · Physics 2018-01-17 T. R. Gentile , P. J. Nacher , B. Saam , T. G. Walker

Magnetic Resonance Imaging (MRI) can be considered one of the most effective techniques in both clinical diagnostic medical field and biomedicine, as it allows to obtain images anatomy of the body and its various parts and information…

Fluid Dynamics · Physics 2011-02-02 Stefania Nicolosi

Magnetic Resonance Imaging (MRI) has become one of the most important tools to screen humans in medicine, virtually every modern hospital is equipped with an NMR tomograph. The potential of NMR in 3D imaging tasks is by far greater, but…

Soft Condensed Matter · Physics 2018-09-14 Ralf Stannarius

Sizable hyperpolarisation, i.e. an imbalance of the occupation numbers of nuclear spins in a sample deviating from thermal equilibrium, is needed in various fields of science. For example, hyperpolarised tracers are utilised in magnetic…

The structure of the excited $2^{3}$S and $2^{3}$P triplet states of $^{3}$He and $^{4}$He in an applied magnetic field B is studied using different approximations of the atomic Hamiltonian. All optical transitions (line positions and…

Atomic Physics · Physics 2009-11-07 E. Courtade , F. Marion , P. -J. Nacher , G. Tastevin , K. Kiersnowski , T. Dohnalik

Fetal Magnetic Resonance Imaging at low field strengths is emerging as an exciting direction in perinatal health. Clinical low field (0.55T) scanners are beneficial for fetal imaging due to their reduced susceptibility-induced artefacts,…

We describe a 3He magnetometer capable to measure high magnetic fields (B > 0.1 Tesla) with a relative accuracy of better than 10^-12. Our approach is based on the measurement of the free induction decay of gaseous, nuclear spin polarized…

Instrumentation and Detectors · Physics 2015-06-19 A. Nikiel , P. Blümler , W. Heil , M. Hehn , S. Karpuk , A. Maul , E. Otten , L. M. Schreiber , M. Terekhov

We report high steady-state nuclear polarization of 1 torr $^3$He gas nuclei via metastability-exchange optical pumping at magnetic fields above 2 T. The introduction of highly polarized $^3$He gas into Brookhaven's Electron Beam Ion Source…

Instrumentation and Detectors · Physics 2019-04-15 J. D. Maxwell , J. Alessi , G. Atoian , E. Beebe , C. S. Epstein , R. G. Milner , M. Musgrave , A. Pikin , J. Ritter , A. Zelenski

We have used resonant photoemission with circular polarized light as a new tool to obtain information about the electronic structure of half-metals. After careful sample surface preparation of La0.7Sr0.3MnO3, we have obtained a dichroic…

Materials Science · Physics 2018-06-06 M. C. Richter , O. Heckmann , B. S. Mun , C. S. Fadley , B. Mercey , K. Hricovini

We propose a new method to detect short-range \textit{P-} and \textit{T-} violating interactions between nucleons, based on measuring the precession frequency shift of polarized $^3$He nuclei in the presence of an unpolarized mass. To…

Nuclear Experiment · Physics 2012-03-20 W. Zheng , H. Gao , B. Lalremruata , Y. Zhang , G. Laskaris , W. M. Snow , C. B. Fu

Following the first experiment on three-body photodisintegration of polarized $^3$He utilizing circularly polarized photons from High Intensity Gamma Source (HI$\gamma$S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure…

Nuclear Experiment · Physics 2014-11-20 Q. Ye , G. Laskaris , H. Gao , W. Chen , W. Zheng , X. Zong , T. Averett , G. D. Cates , W. A. Tobias

We describe a method to hyperpolarize 3He nuclear spins at high magnetic fields (4.7 Tesla) solely by a magnetized plasma. The conditions for such a magnetized plasma are fulfilled when the mean free path of the free electrons is much…

Atomic Physics · Physics 2018-12-12 A. Maul , P. Blümler , P. -J. Nacher , E. Otten , G. Tastevin , W. Heil
‹ Prev 1 2 3 10 Next ›