超极化气体氙-129的低场NMR测量
收稿日期: 2015-10-22
修回日期: 2016-07-10
网络出版日期: 2016-09-05
基金资助
国家自然科学基金资助项目（81227902，11174327）.
Measuring Polarization of Hyperpolarized Xenon-129 Gas with Low-Field NMR
Received date: 2015-10-22
Revised date: 2016-07-10
Online published: 2016-09-05
在自旋交换光泵过程中，多种参数可能会影响到最终可获得的超极化气体氙-129核自旋极化度．通过低场（0.002 T）核磁共振（NMR）系统研究了连续流动工作模式的自旋交换光泵过程，当混合工作气体流量为0.3 SLPM和0.5 SLPM时，实验测量得到最佳光泵泡工作温度；对于同位素富集和自然丰度的氙-129气体，核自旋极化度的建立时间分别为15 min和22 min．由于混合工作气体的压力以及组分会导致铷原子吸收线的频移和展宽，并且影响到其线型，实验通过低场NMR系统测量确定了用于自旋交换光泵的最佳激光工作波长．低场NMR测量为获得具有高核自旋极化度的超极化气体氙-129，并且能够用于人体肺部MRI研究提供了实验依据．
关键词： 低场核磁共振; 超极化气体氙-129; 自旋交换光泵
赵修超 , 孙献平 , 袁亚平 , 石磊 , 叶朝辉 , 周欣 . 超极化气体氙-129的低场NMR测量[J]. 波谱学杂志, 2016 , 33(3) : 458 -467 . DOI: 10.11938/cjmr20160311
Polarization of hyperpolarized xenon-129 gas prepared by spin exchange optical pumping (SEOP) is affected by many operating parameters. In this study, we measured polarization of hyperpolarized xenon-129 gas on a low field (0.002 T) NMR system, and used the results of such measurements to optimize the operating parameters of SEOP. The optimal operating temperature was first determined. Then the optimal building time for isotopically enriched and naturally abundant xenon-129 gases was determined to be 15 min and 22 min, respectively. The pressure and composition of the gases in the optical pumping process were then optimized to minimize spectral shift, broadening and lineshape change of the rubidium atom absorption lines. Finally, the optimal laser wavelength was determined. In conclusion, measuring polarization of hyperpolarized xenon-129 gas with low-field NMR provides an experimental basis for optimizing operating parameters of SEOP.
[1] Hatabu H, Alsop D C, Listerud J, et al. T2* and proton density measurement of normal human lung parenchyma using submillisecond echo time gradient echo magnetic resonance imaging[J]. Eur J Radiol, 1999, 29(3): 245-252.
[2] Stock K W, Chen Q, Hatabu H, et al. Magnetic resonance T2* measurements of the normal human lung in vivo with ultrashort echo times[J]. Magn Reson Imaging, 1999, 17(7): 997-1 000.
[3] Ohno Y, Koyama H, Yoshikawa T, et al. T2* measurements of 3-T MRI with ultrashort TEs: Capabilities of pulmonary function assessment and clinical stage classification in smokers[J]. Am J Roentgenol, 2011, 197(2): W279-W285.
[4] Salerno M, Altes T A, Mugler J P, et al. Hyperpolarized noble gas MR imaging of the lung: Potential clinical applications[J]. Eur J Radiol, 2001, 40(1): 33-44.
[5] van Beek E J, Wild J M, Kauczor H U, et al. Functional MRI of the lung using hyperpolarized 3-helium gas[J]. J Magn Reson Imaging, 2004, 20(4): 540-554.
[6] Möller H E, Chen X J, Saam B, et al. MRI of the lungs using hyperpolarized noble gases[J]. Magn Reson Med, 2002, 47(6): 1 029-1 051.
[7] Fain S, Schiebler M L, McCormack D G, et al. Imaging of lung function using hyperpolarized helium-3 magnetic resonance imaging: review of current and emerging translational methods and applications[J]. J Magn Reson Imaging, 2010, 32(6): 1 398-1 408.
[8] Matsuoka S, Patz S, Albert M S, et al. Hyperpolarized gas MR imaging of the lung: Current status as a research tool[J]. J Thorac Imaging, 2009, 24(3): 181-188.
[9] Li Hai-dong(李海东), Zhang Zhi-ying(张智颖), Han Ye-qing(韩叶清), et al. Lung MRI using hyperpolarized gases(超极化气体肺部磁共振成像)[J]. Chinese J Magn Reson(波谱学杂志), 2014, 31(3): 307-320.
[10] Ruan Wei-wei(阮伟伟), Zhong Jian-ping(钟俭平), Han Ye-qing(韩叶清), et al. Visualize diffusion map of COPD rat with hyperpolarized Xenon MRI(超极化Xenon对慢阻肺的可视化加权成像)[J]. Chinese J Magn Reson(波谱学杂志), 2015, 32(2): 261-271.
[11] Appelt S, Ben-Amar Baranga A, Erickson C J, et al. Theory of spin-exchange optical pumping of 3He and 129Xe[J]. Phys Rev A, 1998, 58(2): 1 412-1 439.
[12] Babcock E, Chann B, Walker T G, et al. Limits to the polarization for spin-exchange optical pumping of 3He[J]. Phys Rev Lett, 2006, 96(8): 083003.
[13] Rao M, Robb F, Wild J M. Dedicated receiver array coil for 1H lung imaging with same-breath acquisition of hyperpolarized 3He and 129Xe gas[J]. Magn Reson Med, 2015, 74(1): 291-299.
[14] Mayo J R, Hayden M E. Hyperpolarized helium-3 diffusion imaging of the lung[J]. Radiology, 2002, 222(1): 8-11.
[15] Yablonskiy D A, Sukstanskii A L, Quirk J D, et al. Probing lung microstructure with hyperpolarized noble gas diffusion MRI: Theoretical models and experimental results[J]. Magn Reson Med, 2014, 71(2): 486-505.
[16] Owrangi A M, Wang J X, Wheatley A, et al. Quantitative 1H and hyperpolarized 3He magnetic resonance imaging: comparison in chronic obstructive pulmonary disease and healthy never-smokers[J]. Eur J Radiol, 2014, 83(1): 64-72.
[17] Woodhouse N, Wild J M, Palesy M N J, et al. Combined helium-3/proton magnetic resonance imaging measurement of ventilated lung volumes in smokers compared to never-smokers[J]. J Magn Reson Imaging, 2005, 21(4): 365-369.
[18] Friar J L, Gibson B F, Payne G L, et al. Neutron polarization in polarized 3He targets[J]. Phys Rev C. 1990, 42(2): 2 310-2 314.
[19] Stoner R E, Rosneberry M A, Wright J T, et al. Demonstration of a two species noble gas master[J]. Phys Rev Lett, 1996, 77(19): 3 971-3 974.
[20] Goodson B M. Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials, and organisms[J]. J Magn Reson, 2002, 155(2): 157-216.
[21] Walker T G, Happer W. Spin-exchange optical pumping of noble-gas nuclei[J]. Rev Mod Phys, 1997, 69(2): 629-642.
[22] Happer W, Miron E, Schaefer S, et al. Polarization of the nuclear spins of noble-gas atoms by spin exchange with optically pumped alkali-metal atoms[J]. Phys Rev A, 1984, 29(6): 3 092-3 110.
[23] Zook A L, Adhyaru B B, Bowers C R, et al. High capacity production of >65% spin polarized xenon-129 for NMR spectroscopy and imaging[J]. J Magn Reson, 2002, 159(2): 175-182.
[24] Whiting N, Nikolaou P, Eschmann N A, et al. Using frequency-narrowed, tunable laser diode arrays with integrated volume holographic gratings for spin-exchange optical pumping at high resonant fluxed and xenon densities[J]. Appl Phys B, 2012, 106(4): 775-788.
[25] Couture A H, Clegg T B, Driehuys B. Pressure shifts and broadening of the Cs D1 and D2 lines by He, N2, and Xe at densities used for optical pumping and spin exchange polarization[J]. J Appl Phys, 2004, 104(9): 094812.
[26] Romalis M V, Miron E, Cates G D. Pressure broadening of Rb D1 and D2 lines by 3He, 4He, N2, and Xe: Line cores and near wings[J]. Phys Rev A, 1997, 56(6): 4 569-4 578.
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