Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Patent
1995-08-18
1997-03-25
Arana, Louis M.
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
324309, G01V 300
Patent
active
056148267
ABSTRACT:
A composite spin lock prepulse method compensates for magnetic field inhomogeneities in objects or materials under study using nuclear magnetic resonance (NMR). The effective magnetic field seen by an object or material under study using NMR often is characterized by an off-resonance component, which results in the magnetization of the object or material having a component that diverges from the intended orientation after RF pulses. The method according to the present invention recognizes and utilizes the observation that aligning the off-resonance component of the magnetization in the x-z plane can be achieved when the amplitude of a preceding 90.degree. y flip pulse is known, and that the effective field can be placed in alignment with the resulting magnetization, if necessary or desired, by adjusting the amplitude of the locking pulse as a function of the amplitude of the flip pulse. The method has been found to be particularly useful for enhancing contrast in images obtained using magnetic resonance imaging (MRI), and it may be conveniently applied in this and a wide variety of other NMR applications because pulse sequences of the present invention can be conveniently be inserted into existing NMR pulse sequences. In addition, the method may be used to create prepulse sequences having reduced net effective field amplitude and, thus, reduced SAR (heat absorption).
REFERENCES:
patent: 5262724 (1993-11-01), Tanttu
patent: 5270652 (1993-12-01), Dixon et al.
patent: 5281917 (1994-01-01), Santyr
patent: 5347217 (1994-09-01), Leach et al.
patent: 5378985 (1995-01-01), Hinks
Friedrich, Jan O., Frequency and Spatial Selectivity in Nuclear Magnetic Resonance Spectroscopy, University of Oxford (United Kingdom), vol. 50-09B, 1988, p. 4066; Abstract.
Eberhardt, K. E. W., et al., 3D-MR Myelography (3D-MRM) for the Diagnosis of Lumbal Nerve Root Compression Syndrome. A Comparison with Conventional Myelography, Aktuelle Radiologie (Germany), Neuroradiologische Abstract, vol. 4, No. 6, pp. 313-317, 1994-11, Abstract.
Edelman, R. R., et al., Breath-hold MR Angiography of Human Coronary Arteries - EDB, Seventy Seventh Assembly and Annual Meeting of the Radiological Society of North America; pp. 97-98, 1991, Abstract.
Henrich, D., et al., Three-Dimensional MR Movies - EDB, Seventy Sixth Scientific Assembly and Annual Meeting of the Radiological Society of North America, p. 186, 1990, Abstract.
Skalej, M., et al., Snapshot MR Imaging, Dynamic Motion Study of Stomach Peristalsis, Proceedings of the 75th Anniversary Scientific Assembly and Annual Meeting Radiological Society of North America, p. 412, 1989, Abstract.
Icenogle, M.V., et al., Mapping Flow Streamlines by Multistripe Tagging - INS, Journal of Magnetic Resonance, vol. 100, No. 2, pp. 376-381, Nov. 1992, Abstract.
Connelly, A., et al., Outer Volume Suppressed Image related in Vivo Spectroscopy (OSIRIS), a High-Sensitivity Localization Technique, Journal of Magnetic Resonance, vol. 78, No. 3, pp. 519-525, Jul. 1988, Abstract.
Friedrich, J. and R. Freeman, Spatial Localization Using a `Straddle Coil`, Journal of Magnetic Resonance, vol. 77, No. 1, pp. 101-118, Mar. 1988, Abstract.
Shaka, A.J. and R. Freeman, `Prepulses` for Spatial Localization, Journal of Magnetic Resonance, vol. 64, No. 1, pp. 145-150, Aug. 1985, Abstract.
Richards, P.M., et al., Nuclear-Magnetic-Resonance Echo Enhancement in an Antiferromagnet, Physical Review B(Solid State), vol. 4, No. 7, pp. 2216-2224, Oct. 1, 1971, Abstract.
Eberhardt, K.E., et al., 3D-MR Myelography in Diagnosis of Lumbar Spinal Nerve Root Compression Syndromes. Comparative Study With Conventional Myelography?, Aktuelle, Radiol, vol. 4, No. 6, pp. 313-317, Nov. 1994, Abstract.
Tanigawa, K., et al., Magnetic Resonance Imaging Detection of Aortic and Pulmonary Artery Wall Thickening in the Acute Stage of Takayasu Arteritis. Improvement of Clinical and Radiologic Findings After Steroid Therapy, Arthritis Rheum., vol. 35, No. 4, pp. 476-480, Apr. 1992, Abstract.
Seelos, K.C., et al., MR Aniography of Congenital Heart Disease: Value of Segmented Two-Dimensional Inflow Technique and Maximum-Intensity-Protection Display, J. Magn. Reson. Imaging, vol. 4, No. 1, pp. 29-36, Jan.-Feb. 1994, Abstract.
Vandenberg, J.I., et al., Intracellular pH Recovery During Respiratory Acidosis in Perfused Hearts, Am. J. Physiol, vol. 266, No. 2, Pt. 1, pp. C489-497. Feb. 1994, Abstract.
Grace, A.A., et al., Regulation of Intracellular pH in the Perfused Heart by External HC03 - and Na(+)-H+ Exchange, Am. J. Physiol, vol. 265, No. 1, Pt. 2, pp. H289-298, Jul. 1993, Abstract.
Wilke, N., et al., Contrast-Enhanced First Pass Myocardial Perfusion Imaging: Correlation Between Myocardial Blood Flow in Dogs at Rest and During Hyperemia, Magn. Reson. Med., vol. 29, No. 4, pp. 485-497, Apr. 1993, Abstract.
Klose, U., Mapping of the Radio Frequency Magnetic Field with a MR Snapshot FLASH Technique, Med. Phys., vol. 19, No. 4, pp. 1099-1104, Jul.-Aug. 1992, Abstract.
Chien, D., et al., High-Speed Black Blood Imaging of Vessel Stenosis in the Presence of Pulsatile Flow, J. Magn. Reson. Imaging, vol. 2, No. 4, pp. 437-441, Abstract.
Matthaei, D., et al., Fast Inversion Recovery T1 Contrast and Chemical Shift Contrast in High-Resolution Snapshot FLASH MR Images, Magn. Reson. Imaging, Vo. 10, No. 1, pp. 1-6, 1992, Abstract.
Bensal, N. and R. L. Nunnally, Improved MR Imaging in Extremely Inhomogeneous Radio-Frequency Fields, Magn. Reson. Imaging, vol. 9, No. 1, pp. 61-65, 1991, Abstract.
Anderson, S.E., et al., Na-H Exchange in Myocardium: Effects of Hypoxia and Acidification on Na and Ca., Am. J. Physiol., vol. 259, No. 6, Pt. 1, C940-8, Dec. 1990, Abstract.
Henrich, D., et al., 3-D snapshot Flash NMR Imaging of the Human Heart, Magn. Reson. Imaging, vol. 8, No. 4, pp. 377-379, 1990, Abstract.
Bourgeois, D., et al., High-Flux Signals and Spatial Localization in High-Resolution 1H Spectroscopy with Surface Coils, Magn. Reson. Med., vol. 11, No. 2, pp. 275-281, Aug. 1989, Abstract.
Ordidge, R. J., et al., A General Approach to Selection of Multiple Cubic Volume Elements Using the ISIS Techniqu, Magn. Reson. Med., vol. 8, No. 3, pp. 323-331, Nov. 1988, Abstract.
Ordidge, R. J., Randon Noise Selective Excitation Pulses, Magn. Reson. Med., vol. 5, pp. 93-98, No. 1, Jul. 1987, Abstract.
Purdy, David E., "Method for 3-D Magnetic Resonance Imaging", Patent 5,180,981, Patent application No. 616522 filed Nov. 21, 1990, patent date Jan. 19, 1993, Abstract.
Ehman, R.L. and J. P. Felmlee, Method for Reducing Artifacts in NMR Images, Request for Reexamination No. 90/003,739, Feb. 21, 1995; B1,4,715,383 (2708th); Reexamination Certificate for Patent 4,715,383 issued Dec. 29, 1987.
Freeman, R., et al., Radiofrequency Pulse Sequences Which Compensate Their Own Imperfections, Physical Chemistry Laboratory, Oxford, England, Received Sep. 13, 1979, Journal of Magnetic Resoance 38, 453-479 (1980).
Levitt, M.H., Composite Pulses, Progress in Nuclear Magnetic Resonance Spectroscopy, vol. 18, pp. 61-122, 1986.
Principles of MR Imaging, Phillips, Medical Systems, pp. 9-65.
Santyr, G. E., et al., Off-Resonance Spin Locking for MR Imaging, Departments of Medical Physics and Radiology, University of Wisconsin, Madison, Wisconsin, received Jul. 6, 1993, revised Dec. 21, 1993, accepted Mar. 15, 1994, pp. 43-50.
Cardiac Magnetic Resonance Imaging - A Philips Medical Systems Clinical Applications Series, Basic Principles, MR Clinical Application Series, Philips, pp. 2-15.
Brittain, Jean H., et al., Coronary Angiography with Magnetization-Prepared T.sub.2 Contrast, Magnetic Resonance Systems Research Laboratory, Stanford University, MRM 33:689-696 (1995).
Parrar, Thomas C., Pulse Nuclear Megnetic Resonance Spectroscopy - An Introduction to the Theory and Applications, Department of Chemistry, University of Wisconsin, Madison, Wisconsin, Preface, The Parragut Press, Chicago, 1987.
Sepponen, R.E., et al., Multiple Slice Spin Lock Sequence - An Effective Method for T1.sub.p Imaging, Soc. Mag. Res. Med., p. 1218, 1993.
Brittain, J.H., et al., Multislice Coronary Agiography
Arana Louis M.
Emory University
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