High-volume production of laser-polarized 129Xe

Driehuys, Bastiaan; Cates, G. D.; Miron, E.; Sauer, Karen L.; Walter, D. K.; Happer, W.

doi:10.1063/1.117022

Cited by 333 publications

(311 citation statements)

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“…The state of the art Xe-129 polarization method uses continuous flow spin-exchange polarization systems in combination with high powered (40 -200 W) lasers (41,42). In this method, depolarization is reduced by freezing the polarized nuclei in the solid state using a liquid N 2 cold finger (43,44). Recent breakthroughs using enriched Xe-129 have made polarization levels delivered to the subject comparable to those achieved with He-3 (45).…”

Section: Hyperpolarized Gas Agentsmentioning

confidence: 99%

Functional lung imaging using hyperpolarized gas MRI

Fain

Korosec

Holmes

et al. 2007

Magnetic Resonance Imaging

178

158

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The noninvasive assessment of lung function using imaging is increasingly of interest for the study of lung diseases, including chronic obstructive pulmonary disease (COPD) and asthma. Hyperpolarized gas MRI (HP MRI) has demonstrated the ability to detect changes in ventilation, perfusion, and lung microstructure that appear to be associated with both normal lung development and disease progression. The physical characteristics of HP gases and their application to MRI are presented with an emphasis on current applications. Clinical investigations using HP MRI to study asthma, COPD, cystic fibrosis, pediatric chronic lung disease, and lung transplant are reviewed. Recent advances in polarization, pulse sequence development for imaging with Xe-129, and prototype low magnetic field systems dedicated to lung imaging are highlighted as areas of future development for this rapidly evolving technology.

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Section: Hyperpolarized Gas Agentsmentioning

confidence: 99%

Functional lung imaging using hyperpolarized gas MRI

Fain

Korosec

Holmes

et al. 2007

Magnetic Resonance Imaging

178

158

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“…9800, Amersham Health, Durham, NC). A gas mixture of 1% natural abundance 129 Xe, 10% N 2 , and 89% 4 He flowed at a rate of 0.9 l/min through an optical cell where the 129 Xe spins were polarized via spin exchange with optically pumped Rb vapor (24). HpXe was accumulated for 30 min and frozen at liquid nitrogen temperature.…”

Section: Methodsmentioning

confidence: 99%

Characterization of diffusing capacity and perfusion of the rat lung in a lipopolysaccaride disease model using hyperpolarized ¹²⁹Xe

Månsson

Wolber

Driehuys³

et al. 2003

Magnetic Resonance in Med

106

156

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The ability to quantify pulmonary diffusing capacity and perfusion using dynamic hyperpolarized 129 Xe NMR spectroscopy is demonstrated. A model of alveolar gas exchange was developed, which, in conjunction with 129 Xe NMR, enables quantification of average alveolar wall thickness, pulmonary perfusion, capillary diffusion length, and mean transit time. The technique was employed to compare a group of naïve rats (n ‫؍‬ 10) with a group of rats with acute inflammatory lung injury (n ‫؍‬ 10), caused by instillation of lipopolysaccaride (LPS). The measured structural and perfusion-related parameters were in agreement with reported values from studies using non-NMR methods. Significant differences between the groups were found in total diffusion length (control 8.5 ؎ 0.5 m, LPS 9.9 ؎ 0.6 m, P < 0.001), in capillary diffusion length (control 2.9 ؎ 0.4 m, LPS 3.9 ؎ 1.0 m, P < 0.05), and in pulmonary hematocrit (control 0.55 ؎ 0.06, LPS 0.43 ؎ 0.08, P < 0.01), whereas no differences were observed in alveolar wall thickness, pulmonary perfusion, and mean transit time. These results demonstrate the ability of the method to distinguish two main aspects of lung function, namely, diffusing capacity and pulmonary perfusion. Key words: hyperpolarized gas NMR; xenon-129; lung function; diffusing capacity; pulmonary perfusion Gas transfer from ambient air to the blood involves different transport mechanisms. Alveolar ventilation is accomplished by convective transport. Gas transfer within the alveolus and from the alveolus into the blood stream occurs by diffusion along concentration gradients. The blood is then transported from the lungs to peripheral tissues by the pulmonary circulation. These transport processes are affected by a number of lung diseases. Convective transport in the airways is impaired in obstructive lung diseases (1). Diffusion impairment occurs in interstitial lung diseases as well as in pulmonary edema (2). The pulmonary vasculature is affected by both primary lung disease and by left heart failure, causing abnormalities in blood flow (3).The most common method of assessment of diffusion in the alveolar-capillary unit is measurement of the diffusing capacity for carbon monoxide, DL CO (4). The diffusing capacity is defined as the total rate of gas passage across the alveolar-capillary membrane per unit of partial pressure difference of the gas. The tracer gas carbon monoxide diffuses across the alveolar-capillary barrier and is tightly bound to hemoglobin in the erythrocytes. In addition to factors determining diffusion, e.g., the available surface area and the diffusion path length, DL CO therefore depends also on the availability of binding sites, i.e., on hemoglobin concentration and on perfusion. DL CO provides information about diffusion properties of the lung as a whole, but no regional information about function is obtained. By measurement at different partial pressures for oxygen, DL CO can be subdivided into the membrane conductance and a term reflecting the availability of binding sites. This is...

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“…We have built a Rb-Xe hyperpolarizing unit, similar to that described by Driehuys et al, 8 for the production of several grams of polarized Xe ice. In order to optimize the Rb ͑and thus Xe͒ polarization, a low-cost and compact polarization imaging device was developed which enables measurement of the distribution of the absolute Rb polarization in the pumping cell.…”

mentioning

confidence: 99%

Experimental studies of rubidium absolute polarization at high temperatures

Appelt

Ünlü

Zilles

et al. 1999

Applied Physics Letters

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We report on measurements of the absolute rubidium ͑Rb͒ polarization, optically pumped by a high-power diode laser array, up to temperatures of 180°C. The penetration of the pump laser light into a high-pressure cell has been studied experimentally and theoretically. The experimental results are compared to a model, which describes the local Rb polarization and optical pumping rate in the cell. © 1999 American Institute of Physics. ͓S0003-6951͑99͒03229-5͔In nuclear magnetic resonance and in other fields of science such as human MRI, 1-4 material and surface physics, 5,6 the production of hyperpolarized noble gases through spin exchange with optically pumped alkali-metal atoms has gained importance. For some potential applications such as 129 Xe brain imaging, 4 very high nuclear polarizations are required to circumvent the limitations of the delivery method 7 and to avoid the anaesthetic effects of large quantities of Xe in the brain.We have built a Rb-Xe hyperpolarizing unit, similar to that described by Driehuys et al.,8 for the production of several grams of polarized Xe ice. In order to optimize the Rb ͑and thus Xe͒ polarization, a low-cost and compact polarization imaging device was developed which enables measurement of the distribution of the absolute Rb polarization in the pumping cell. The methodology and first experimental results of absolute Rb polarization imaging in high-pressure optical pumping cells at a temperature of Tϭ100°C were recently published by Baranga et al. 9 and Young et al. 10 Spin exchange optical pumping at temperatures higher than 100°C causes the spin exchange rate between Rb and Xe to be larger and therefore the time required to polarize Xe atoms is significantly shorter.Experimental results of the absolute 85 Rb polarization in high pressure optical pumping cells for temperatures up to 180°C are presented. The measured, volume-averaged absolute Rb polarization sets a limit on the maximum achievable Xe nuclear polarization at high temperatures. Furthermore, we studied the penetration of the pump laser light into the cell at a temperature range from 120-180°C. Figure 1 shows a schematic diagram of the compact, low-cost 85 Rb polarization imaging unit. For the sake of clarity, components of the Rb-Xe polarizer necessary for operating in a flowing mode and to freeze out the Xe gas are not shown. The optical pumping cell consisted of a glass cylinder with flat glass windows in order to avoid lens effects on the pump laser beam. The cell ͑inner diameter 24 mm, length 70 mm͒ was filled with approximately 1 g of Rb, 7 atm of 4 He, and 0.07 atm of N 2 and Xe gas. For optical pumping parallel to the magnetic field B 0 (z axis͒, we use a fiberoptically coupled diode laser array ͑Opto Power Corp., OPC 100͒ with a maximum output power of 100 W and a linewidth of 2 nm. The absolute 85 Rb polarization was measured by detecting, optically in the transverse mode, the Zeeman transitions of 85 Rb in a high magnetic field. The Zeeman spectrum was obtained by sweeping the magnetic field B 0 from 53....

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High-volume production of laser-polarized 129Xe

Cited by 333 publications

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Functional lung imaging using hyperpolarized gas MRI

Functional lung imaging using hyperpolarized gas MRI

Characterization of diffusing capacity and perfusion of the rat lung in a lipopolysaccaride disease model using hyperpolarized ¹²⁹Xe

Experimental studies of rubidium absolute polarization at high temperatures

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High-volume production of laser-polarized 129Xe

Cited by 333 publications

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Functional lung imaging using hyperpolarized gas MRI

Functional lung imaging using hyperpolarized gas MRI

Characterization of diffusing capacity and perfusion of the rat lung in a lipopolysaccaride disease model using hyperpolarized 129Xe

Experimental studies of rubidium absolute polarization at high temperatures

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Characterization of diffusing capacity and perfusion of the rat lung in a lipopolysaccaride disease model using hyperpolarized ¹²⁹Xe