Longitudinal relaxation and diffusion measurements using magnetic resonance signals from laser-hyperpolarized 129Xe nuclei.
Longitudinal relaxation and diffusion measurements using magnetic resonance signals from laser-hyperpolarized 129Xe nuclei.
复制标题
使用来自激光超极化 129Xe 原子核的磁共振信号进行纵向弛豫和扩散测量。
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
Peter T. Fox
中科院分区：
文献类型：
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作者：
B. Patyal;Jianfeng Gao;Robert F. Williams;J. Roby;B. Saam;B. Rockwell;R. Thomas;D. Stolarski;Peter T. Fox
介绍了基于激光超极化129Xe核磁共振信号的T1弛豫和扩散测量方法。这些方法涉及到129Xe易逝超极化磁化的最佳利用。建立了该方法的理论框架，并应用该方法测量了超极化129Xe的纵向弛豫常数T1和自扩散常数D。在含129Xe自然丰度的细胞中，在790 Torr下，在20℃和2.0 T场下，T1值确定为155 +/- 5 min。对于896托的第二个细胞，在相同的场和温度下，T1值确定为66 +/- 2分钟。在7.05 T的较高电场下，两个细胞的T1值分别为185 +/- 10和88 +/- 5 min。第一个电池的129Xe自扩散常数为0.057 cm2/s，第二个电池的129Xe自扩散常数为0.044 cm2/s。该方法适用于129Xe气相，体外；然而，它们原则上适用于体内或离体研究。讨论了这些方法在发展新近出现的超极化129Xe MRI应用中的潜在作用。
Methods for T1 relaxation and diffusion measurements based on magnetic resonance signals from laser-hyperpolarized 129Xe nuclei are introduced. The methods involve optimum use of the perishable hyperpolarized magnetization of 129Xe. The necessary theoretical framework for the methods is developed, and then the methods are applied to measure the longitudinal relaxation constant, T1, and the self-diffusion constant, D, of hyperpolarized 129Xe. In a cell containing natural abundance 129Xe at 790 Torr, the T1 value was determined to be 155 +/- 5 min at 20 degrees C and at 2.0 T field. For a second cell at 896 Torr, at the same field and temperature, the T1 value was determined to be 66 +/- 2 min. At a higher field of 7.05 T, the T1 values for the two cells were found to be 185 +/- 10 and 88 +/- 5 min, respectively. The 129Xe self-diffusion constant for the first cell was measured to be 0.057 cm2/ s and for the second cell it was 0.044 cm2/s. The methods were applied to 129Xe in the gas phase, in vitro; however, they are, in principle, applicable for in vivo or ex vivo studies. The potential role of these methods in the development of newly emerging hyper-polarized 129Xe MRI applications is discussed.