4985677 Magnetic resonance imaging and spectroscopy using an excitation pulse for multiple-dimensional selectivity

4985677 Magnetic resonance imaging and spectroscopy using an excitation pulse for multiple-dimensional selectivity

Mognelic Resonance Printed in the USA. Imaging, Vol. 10, pp. All rights reserved. 1-1X, 1992 Copyright 0730-725X/92 $5.00 + .OO Q 1992 Pergamon Pr...

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Mognelic Resonance Printed in the USA.

Imaging, Vol. 10, pp. All rights reserved.

1-1X,

1992 Copyright

0730-725X/92 $5.00 + .OO Q 1992 Pergamon Press Ltd.

NEW PATENT!3 This Section contains abstracts and, where appropriate, illustrations of recently issued United States patents and published patent applications filed from over 30 countries under the Patent Cooperation Treaty. This information was obtained from recent additions to the Pergamon PATSEARCH@ online database in accordance with interest profiles developed by the Editors. Further information about Pergamon PATSEARCHB can be obtained from Pergamon Orbit InfoLine Inc., 8000 Westpark Drive, McLean, Virginia 22102, U.S.A. Copies of complete patents announced in this Section are available from Pergamon Orbit InfoLine Inc. for $8 per copy. Payment with order is required. Orders outside North America add $2 for air postage. Order by patent numbef for Pergamon Orbit InfoLine only.

4984573 METHOD OF ELECTRON SPIN RESONANCE ENHANCED MAGNETIC RESONANCE IMAGING Ib Leunbach, Drag Denmara assigned to Hafslund Nycomed Innovation AB A method of generating a magnetic resonance image of a sample comprising introducing into the sample a contrast medium comprising a paramagnetic material having an electron spin resonance transition having a linewidth of 1 Gauss or less; exposing the sample to a first radiation of a frequency selected to excite nuclear spin transitions in selective nuclei in the sample and exposing the sample to a second radiation of a frequency which excites electron spin transitions coupled to nuclear spin transitions of at least some nuclei, the second radiation being of a frequency selected to excite an electron spin resonance transition of the paramagnetic material; detecting free induction decay signals from the sample; and generating therefrom a magnetic resonance image of the sample.

4984574 NONINVASIVE FETAL OXYGEN MONITOR USING NMR Set Goldberg, Jonothan

L Logan

A non-invasive method for continuously monitoring blood and tissue oxygenation of a human fetus prior to and during labor and delivery. A specialized NMR spectrometer, whose static-field magnet is large enough to admit the abdomen of a pregnant woman at term, obtains resonance signals from a spatial region within the mother that includes the fetus.

Resonance signals originating from the oxygentransport protein hemoglobin are continuously obtained and analyzed. Signals originating from the special form of hemoglobin found in the fetal circulation are distinguished from those from the adult form of hemoglobin found in the maternal circulation. By continuously comparing the amplitudes of specific fetal hemoglobin resonances that are characteristically shifted upon oxygen binding with the amplitudes of other fetal hemoglobin resonances that are not so shifted, the method yields a continuous measurement of fetal blood and tissue oxygenation. Further analysis of the resonance signals yields indications of fetal blood acidity, heartbeat and respiration and corresponding indications of maternal condition. The method is also applicable to newborn infants and to certain mammals other than humans.

4985677 MAGNETIC RESONANCE IMAGING AND SPECTROSCOPY USING AN EXCITATION PULSE FOR MULTIPLE-DIMENSIONAL SELECTIVITY John M Pauly assigned to The Board of Trustees of the Leland Stanford Junior University A method of obtaining multi-dimensional spatially-selective magnetic resonance signals from a body includes applying a static magnetic field (Bo) to said body thereby aligning nuclear spins along an axis (z), and applying one or more time-varying magnetic gradients (Gx(t), Gy(t), Gz(t)) during a time period, T. During the time period, T, an RF excitation pulse (Bl) is applied to said body to tip said nuclear spins, said RF excitation pulse being related to said modulated magnetic gradients by a first spatial frequency weighting function (W(k)(t)) whereby magnetic

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New Patents

resonance signals transmitted by said tipped nuclear spins are spatially selective in multi dimensions. The resulting magnetic resonance signals are then detected to provide the multidimensional spatially-selective signals.

4985678 HORIZONTAL FIELD IRON CORE MAGNETIC RESONANCE SCANNER Raymond E Gangarosa, K Ming Chui assigned to Picker International Inc A patient is disposed on a patient couch (A) and positioned longitudinally and vertically to bring a region of interest within the patient into a gap between a pair of magnetic pole pieces (20, 22). Magnetic field driver(s) (50’, 50, 52) generates a magnetic field through a U-shaped ferrous member (B) connected with the pole pieces and through the gap therebetween. The U-shaped ferrous member extends below the gap such that open access is provided to the patient from above. Shielding coils (62,64,66) are disposed between the U-shaped ferrous portion and the gap to compensate for distortion of the magnetic field in the gap attributable to magnetic flux through the IJ-shaped member. Magnetic resonance is excited in the region of interest of the patient between the pole pieces and magnetic resonance signals emanating therefrom are received, such as with a crossed elliptical quadrature coil (72). The received magnetic resonance signals are processed by processing circuitry (E) and image representations for display on a monitor (82).

4985680 RF COIL SYSTEM IN MAGNETIC RESONANCE IMAGING APPARATUS Kazuhik Tsujita, Tomohisa Maeda, assigned to Nishinasunomachi, Japan Kabushiki Kaisha Toshiba An RF coil system having (2n+ 1)/4 (n: zero or a positive integer) wavelength cables arranged in both ends of a PIN diode conneted in series with an RF coil, and a PIN diode is DC-biased via the aforementioned cable. A multi-band RF system constructed by providing a plurality of such wavelength cables corresponding to the fre-

quencies of an RF pulse in obtaining an MR signal. Since the cable is, for example, of a coaxia1 type, the length of the cable is easy to adjust and it is thus possible to avoid coupling to the ambient environment.

4985834 SYSTEM AND METHOD EMPLOYING PIPELINED PARALLEL CIRCUIT ARCHITECTURE FOR DISPLAYING SURFACE STRUCTURES OF THE INTERIOR REGION OF A SOLID BODY Harvey E Cline, Richard Hartley, Siegwal Ludke, Sharbel Noujaim assigned to Genera1 Electric Company Arbitrary interior surfaces of a threedimensional body are displayed from a regular array of values of at least one physical property in the interior of the body. The physical property measurements may be made with systems such as computerized tomographic x-ray, or magnetic resonance imaging. Highly parallel circuits and a highly parallel architecture permit generation of surface views in real time, i.e., sufficiently fast to support ongoing procedures such as surgical operations. These parallel circuits, realizable on large scale integrated circuit chips, perform surface normal calculations, linear interpolations and signal comparisons in simultaneously operating circuit which paths are asynchronously enabled when input data appear.

4986256 USE OF PARAMAGNETIC METALLOPORPHYRINS AS CONTRAST AGENTS FOR TUMORS IN MRI IMAGING Jack S Cohen, Chi-Wan Chen, Charles Myers, Miriam Sohn assigned to The United States of America as represented by the Department of Health and Human Services Water-soluble paramagnetic metalloporphyrins are used as contrast enhancing agents for magnetic resonance imaging. These agents exhibit excellent localization, non-toxicity and suprisingly high contrast enhancement in magnetic resonance imaging applications.