Exploring hyperpolarized 83Kr by remotely detected NMR relaxometry -: art. no. 044312
Exploring hyperpolarized 83Kr by remotely detected NMR relaxometry -: art. no. 044312
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DOI：
10.1063/1.2159493
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发表时间：
2006-01-28
影响因子：
4.4
通讯作者：
Meersmann, T
中科院分区：
文献类型：
--
作者：
Cleveland, ZI;Pavlovskaya, GE;Meersmann, T
具有核电四极矩的超极化（hp）稀有气体首次可用于高场核磁共振（NMR）光谱和磁共振成像。 Hp Kr-83 (I=9/2) 通过自旋交换光泵浦产生，并从泵浦过程中使用的铷蒸气中分离出来。光泵浦发生在先前未研究的高氪气密度条件下。与 9.4 T 磁场强度下的热平衡 Kr-83 信号相比，信号增强了三个数量级以上。 Kr-83 的自旋晶格弛豫主要是由周围容器壁上氪原子短暂吸附期间的四极耦合引起的，并且显着限制了当前获得的自旋极化。使用远程检测的 hp Kr-83 NMR 光谱在 0.05 至 3 T 的场强下对宏观玻璃容器和干燥的犬肺组织进行测量表明，随着磁场强度的降低，纵向弛豫急剧加速。 (c) 2006 年美国物理研究所。
For the first time, a hyperpolarized (hp) noble gas with a nuclear electric quadrupole moment is available for high-field nuclear-magnetic-resonance (NMR) spectroscopy and magnetic-resonance imaging. Hp Kr-83 (I=9/2) is generated by spin-exchange optical pumping and separated from the rubidium vapor used in the pumping process. Optical pumping occurs under the previously unstudied condition of high krypton gas densities. Signal enhancements of more than three orders of magnitude compared to the thermal equilibrium Kr-83 signal at 9.4 T magnetic-field strength are obtained. The spin-lattice relaxation of Kr-83 is caused primarly by quadrupolar couplings during the brief adsorption periods of the krypton atoms on the surrounding container walls and significantly limits the currently obtained spin polarization. Measurements in macroscopic glass containers and in desiccated canine lung tissue at field strengths between 0.05 and 3 T using remotely detected hp Kr-83 NMR spectroscopy reveal that the longitudinal relaxation dramatically accelerates as the magnetic-field strength decreases. (c) 2006 American Institute of Physics.