@article {392, title = {Imaging of laser-polarized solid xenon}, journal = {Solid State Nuclear Magnetic Resonance}, volume = {10}, year = {1998}, note = {Solid State Nucl MagZh559Times Cited:5Cited References Count:16}, month = {Feb}, pages = {247-250}, abstract = {
The enhanced spin polarization produced by optical pumping of gaseous rubidium/xenon samples has made possible a number of recent experiments in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI). Here we report MRI of laser-polarized xenon in the solid phase at low temperature. Due to the high xenon density in the solid phase and the enhanced spin polarization, it is possible to achieve high intensity and spatial resolution of the image. Signals were observed from xenon films solidified onto the glass container walls and not from an enclosed chili pepper. (C) 1998 Elsevier Science B.V.
}, keywords = {gas}, isbn = {0926-2040}, doi = {Doi 10.1016/S0926-2040(97)00078-7}, url = {Because xenon NMR is highly sensitive to the local environment, laser-polarized xenon could be a unique probe of living tissues. Realization of clinical and medical science applications beyond lung airspace imaging requires methods of efficient delivery of laser-polarized xenon to tissues, because of the short spin-lattice relaxation times and relatively low concentrations of xenon attainable in the body. Preliminary results from the application of a polarized xenon injection technique for in vivo Xe-129 NMR/MRI are extrapolated along with a simple model of xenon transit to show that the peak local concentration of polarized xenon delivered to tissues by injection may exceed that delivered by respiration by severalfold.
}, keywords = {humans}, isbn = {0027-8424}, doi = {Doi 10.1073/Pnas.94.26.14725}, url = {The quadrupolar and chemical shift tensors, as well as the relative orientation of the two principle axis systems, are accurately determined using a two-dimensional nuclear magnetic resonance technique. Good agreement between experimental and simulated two-dimensional spectra is obtained for a series of rubidium and sodium compounds at multiple magnetic field strengths. Extension of this technique to correlate the quadrupolar and dipolar interactions, as well as the incorporation of a purely isotropic dimension resulting in a three-dimensional experiment is also discussed. (C) 1996 American Institute of Physics.
}, keywords = {line-shapes}, isbn = {0021-9606}, doi = {Doi 10.1063/1.472776}, url = {Optical pumping with laser light can be used to polarize the nuclear spins of gaseous xenon-129. When hyperpolarized xenon-129 is dissolved in liquids, a time-dependent departure of the proton spin polarization from its thermal equilibrium is observed, The variation of the magnetization is an unexpected manifestation of the nuclear Overhauser effect, a consequence of cross-relaxation between the spins of solution protons and dissolved xenon-129. Time-resolved magnetic resonance images of both nuclei in solution show that the proton magnetization is selectively perturbed in regions containing spin-polarized xenon-129. This effect could find use in nuclear magnetic resonance spectroscopy of surfaces and proteins and in magnetic resonance imaging.
}, keywords = {resonance}, isbn = {0036-8075}, doi = {Doi 10.1126/Science.271.5257.1848}, url = {By means of optical pumping with laser light it is possible to enhance the nuclear spin polarization of gaseous xenon by four to five orders of magnitude, The enhanced polarization has allowed advances in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI), including polarization transfer to molecules and imaging of lungs and other void spaces, A critical issue for such applications is the delivery of xenon to the sample while maintaining the polarization, Described herein is an efficient method for the introduction of laser-polarized xenon into systems of biological and medical interest for the purpose of obtaining highly enhanced NMR/MRI signals. Using this method, we have made the first observation of the time-resolved process of xenon penetrating the red blood cells in fresh human blood-the xenon residence time constant in the red blood cells was measured to be 20.4+/-2 ms. The potential of certain biologically compatible solvents for delivery of laser-polarized xenon to tissues for NMR/MRI is discussed in light of their respective relaxation and partitioning properties.
}, keywords = {gas}, isbn = {0027-8424}, doi = {Doi 10.1073/Pnas.93.23.12932}, url = {A method for NMR investigations of surface nuclei using cross polarization from optically polarized xenon (OPCP) is described. We find this methodology results in enhancement factors of approximately 10(3) upon application to surface protons. The dynamics of Xe-129 transfer to protons is examined in some detail, including the time, temperature, and multiple contact dependences of signal intensities. Furthermore, we discuss the sensitivity of the transfer process to spatial diffusion. Finally, we report on application of the OPCP experiment to a low total surface area sample.
}, keywords = {gel}, isbn = {0937-9347}, url = {