@article {288, title = {Dispersion measurements using time-of-flight remote detection MRI}, journal = {Magnetic Resonance Imaging}, volume = {25}, year = {2007}, note = {Magn Reson Imaging167BHTimes Cited:5Cited References Count:10}, month = {May}, pages = {449-452}, abstract = {

Remote detection nuclear magnetic resonance and magnetic resonance imaging can be used to study fluid flow and dispersion in a porous medium from a purely Eulerian point of view (i.e., in a laboratory frame of reference). Information about fluid displacement is obtained on a macroscopic scale in a long-time regime, while local velocity distributions are averaged out. It is shown how these experiments can be described using the common flow propagator formalism and how experimental data can be analyzed to obtain effective porosity, flow velocity inside the porous medium, fluid dispersion and flow tracing of fluid. (C) 2007 Elsevier Inc. All rights reserved.

}, keywords = {flow}, isbn = {0730-725X}, doi = {Doi 10.1016/J.Mri.2006.11.011}, url = {://WOS:000246425100004}, author = {Granwehr, J. and Harel, E. and Hilty, C. and Garcia, S. and Chavez, L. and Pines, A. and Sen, P. N. and Song, Y. Q.} } @article {319, title = {Time-of-flight flow imaging using NMR remote detection}, journal = {Physical Review Letters}, volume = {95}, year = {2005}, note = {Phys Rev Lett955SGTimes Cited:35Cited References Count:29}, month = {Aug 12}, abstract = {

A time-of-flight imaging technique is introduced to visualize fluid flow and dispersion through porous media using NMR. As the fluid flows through a sample, the nuclear spin magnetization is modulated by rf pulses and magnetic field gradients to encode the spatial coordinates of the fluid. When the fluid leaves the sample, its magnetization is recorded by a second rf coil. This scheme not only facilitates a time-dependent imaging of fluid flow, it also allows a separate optimization of encoding and detection subsystems to enhance overall sensitivity. The technique is demonstrated by imaging gas flow through a porous rock.

}, keywords = {mri}, isbn = {0031-9007}, doi = {Doi 10.1103/Physrevlett.95.075503}, url = {://WOS:000231247300028}, author = {Granwehr, J. and Harel, E. and Han, S. and Garcia, S. and Pines, A. and Sen, P. N. and Song, Y. Q.} } @article {380, title = {NMR and MRI using laser-polarized xenon}, journal = {Spectroscopy}, volume = {14}, year = {1999}, note = {Spectroscopy216AZTimes Cited:19Cited References Count:65}, month = {Jul}, pages = {26-33}, abstract = {

The application of optical pumping methods increases the nuclear spin polarization of noble gases by four to five orders of magnitude. This enormous increase in polarization translates directly into greatly enhanced signals for nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Selected experiments devised to exploit this enhanced sensitivity are reviewed, including xenon NMR/MRI studies of biological systems and polarization transfer to molecules in solution and on surfaces.

}, keywords = {liquid xenon}, isbn = {0887-6703}, url = {://WOS:000081419500003}, author = {Song, Y. Q. and Goodson, B. M. and Pines, A.} } @article {384, title = {Study of xenon binding in cryptophane-A using laser-induced NMR polarization enhancement}, journal = {Journal of the American Chemical Society}, volume = {121}, year = {1999}, note = {J Am Chem Soc189BTTimes Cited:73Cited References Count:64}, month = {Apr 14}, pages = {3502-3512}, abstract = {

In solution, spin-polarization transfer between laser-polarized xenon and the hydrogen nuclei of nearby molecules leads to signal enhancements in the resolved H-1 NMR spectrum, offering new opportunities for probing the chemical environment of xenon atoms. Following binding of laser-polarized xenon to molecules of cryptophane-A, selective enhancements of the H-1 NMR signals were observed. A theoretical framework for the interpretation of such experimental results is provided, and the spin polarization-induced nuclear Overhauser effects are shown to yield information about the molecular environment of xenon. The observed selective H-1 enhancements allowed xenon-proton internuclear distances to be estimated. These distances reveal structural characteristics of the complex, including the preferred molecular conformations adopted by cryptophane-A upon binding of xenon.

}, keywords = {SPECTROSCOPY}, isbn = {0002-7863}, doi = {Doi 10.1021/Ja9841916}, url = {://WOS:000079884800033}, author = {Luhmer, M. and Goodson, B. M. and Song, Y. Q. and Laws, D. D. and Kaiser, L. and Cyrier, M. C. and Pines, A.} } @article {393, title = {Effects of diffusion on magnetic resonance imaging of laser-polarized xenon gas}, journal = {Journal of Chemical Physics}, volume = {108}, year = {1998}, note = {J Chem PhysZh114Times Cited:30Cited References Count:24}, month = {Apr 15}, pages = {6233-6239}, abstract = {

Molecular diffusion during the application of magnetic field gradients can distort magnetic resonance images. A systematic characterization of these distortions in one dimension was performed using highly spin-polarized xenon gas. By varying the strength of the applied gradient and the geometric dimension of the sample, the evolution of these image distortions between the regimes of strong and weak diffusion was observed. These results are compared with numerical simulations. By directly measuring the displacement distribution of the polarized xenon atoms, it is shown that in the weak-diffusion regime the image distortions originate from the restricted diffusive motion near the sample boundaries, in agreement with previous theoretical work. Additionally, it is shown that the effects of diffusion can be utilized to enhance the contrast between the boundaries and bulk in the images of polarized gas samples, and thus may be exploited as a means of boundary detection in such systems. (C) 1998 American Institute of Physics. [S0021-9606(98)02915-8].

}, keywords = {xe-129}, isbn = {0021-9606}, doi = {Doi 10.1063/1.476030}, url = {://WOS:000073073700018}, author = {Song, Y. Q. and Goodson, B. M. and Sheridan, B. and de Swiet, T. M. and Pines, A.} } @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 = {://WOS:000073123500009}, author = {Song, Y. Q. and Taylor, R. E. and Pines, A.} } @article {420, title = {In vivo NMR and MRI using injection delivery of laser-polarized xenon}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {94}, year = {1997}, note = {P Natl Acad Sci USAYn574Times Cited:55Cited References Count:39}, month = {Dec 23}, pages = {14725-14729}, abstract = {

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 = {://WOS:000071182800090}, author = {Goodson, B. M. and Song, Y. Q. and Taylor, R. E. and Schepkin, V. D. and Brennan, K. M. and Chingas, G. C. and Budinger, T. F. and Navon, G. and Pines, A.} } @article {409, title = {Selective enhancement of NMR signals for alpha-cyclodextrin with laser-polarized xenon}, journal = {Angewandte Chemie-International Edition in English}, volume = {36}, year = {1997}, note = {Angew Chem Int EditYh944Times Cited:48Cited References Count:29}, month = {Nov 14}, pages = {2368-2370}, keywords = {solids}, isbn = {0570-0833}, doi = {Doi 10.1002/Anie.199723681}, url = {://WOS:A1997YH94400025}, author = {Song, Y. Q. and Goodson, B. M. and Taylor, R. E. and Laws, D. D. and Navon, G. and Pines, A.} } @article {407, title = {SQUID detected NMR of laser-polarized xenon at 4.2 K and at frequencies down to 200 Hz}, journal = {Chemical Physics Letters}, volume = {272}, year = {1997}, note = {Chem Phys LettXh440Times Cited:18Cited References Count:32}, month = {Jun 27}, pages = {245-249}, abstract = {

A spectrometer based on a dc SQUID (superconducting quantum interference device) was used to record nuclear magnetic resonance signals from laser-polarized Xe-129 at 4.2 K and at frequencies ranging from about 200 Hz to 110 kHz in magnetic fields varying from about 0.02 to 9 mT. The Xe-129 resonance linewidths were found to increase with increasing magnetic field, and, at a given field, to increase with higher Xe-129 concentration. The spin-lattice relaxation times were observed to decrease from similar to 8000 s at 5 mT to similar to 2000 s at fields below 0.05 mT. Such long relaxation times make possible a variety of spin polarization transfer experiments. (C) 1997 Published by Elsevier Science B.V.

}, keywords = {relaxation}, isbn = {0009-2614}, doi = {Doi 10.1016/S0009-2614(97)88016-5}, url = {://WOS:A1997XH44000017}, author = {TonThat, D. M. and Ziegeweid, M. and Song, Y. Q. and Munson, E. J. and Appelt, S. and Pines, A. and Clarke, J.} } @article {426, title = {Enhancement of solution NMR and MRI with laser-polarized xenon}, journal = {Science}, volume = {271}, year = {1996}, note = {ScienceUc778Times Cited:230Cited References Count:41}, month = {Mar 29}, pages = {1848-1851}, abstract = {

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 = {://WOS:A1996UC77800041}, author = {Navon, G. and Song, Y. Q. and Room, T. and Appelt, S. and Taylor, R. E. and Pines, A.} } @article {433, title = {NMR of laser-polarized xenon in human blood}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {93}, year = {1996}, note = {P Natl Acad Sci USAVt054Times Cited:92Cited References Count:27}, month = {Nov 12}, pages = {12932-12936}, abstract = {

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 = {://WOS:A1996VT05400048}, author = {Bifone, A. and Song, Y. Q. and Seydoux, R. and Taylor, R. E. and Goodson, B. M. and Pietrass, T. and Budinger, T. F. and Navon, G. and Pines, A.} } @article {453, title = {High-Field Cross-Polarization Nmr from Laser-Polarized Xenon to Surface Nuclei}, journal = {Applied Magnetic Resonance}, volume = {8}, year = {1995}, note = {Appl Magn ResonRt202Times Cited:30Cited References Count:17}, pages = {373-384}, abstract = {

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 = {://WOS:A1995RT20200005}, author = {Gaede, H. C. and Song, Y. Q. and Taylor, R. E. and Munson, E. J. and Reimer, J. A. and Pines, A.} } @article {439, title = {Spin-Polarized Xe-129 Gas Imaging of Materials}, journal = {Journal of Magnetic Resonance Series A}, volume = {115}, year = {1995}, note = {J Magn Reson Ser ARl474Times Cited:49Cited References Count:23}, month = {Jul}, pages = {127-130}, keywords = {xenon}, isbn = {1064-1858}, doi = {Doi 10.1006/Jmra.1995.1157}, url = {://WOS:A1995RL47400017}, author = {Song, Y. Q. and Gaede, H. C. and Pietrass, T. and Barrall, G. A. and Chingas, G. C. and Ayers, M. R. and Pines, A.} }