Determine Fluid Flow Rate Patents (Class 324/306)
  • Publication number: 20080084206
    Abstract: With the objective of easily drawing a flow such as a bloodstream in a subject at low luminance, there is provided a magnetic resonance imaging apparatus including a static magnetic field forming unit, a transmission unit which transmits a plurality of inversion RF pulses to a subject lying in a static magnetic field plural times within one repetition time after transmission of one excitation RF pulse thereby to excite spins of the subject, a gradient magnetic field application unit, a data acquisition unit which acquires magnetic resonance signals encoded by the gradient magnetic field, and an image generation unit which generates an image of the subject based on the magnetic resonance signals acquired by the data acquisition unit. The gradient magnetic field application unit applies velocity encode gradient pulses inverted to one another in polarity to the subject within transmission interval times for the plural RF pulses transmitted to the subject.
    Type: Application
    Filed: October 3, 2007
    Publication date: April 10, 2008
    Inventor: Mitsuharu Miyoshi
  • Patent number: 7343193
    Abstract: A 3D projection reconstruction pulse sequence is employed during a CEMRA dynamic study to acquire a time course series of k-space data sets. Signals from non-vascular voxels are suppressed by reconstructing a corresponding series of low resolution images using the centers of the acquired k-space data sets, and measuring the degree to which the signal behavior of voxels therein differ from a model of unwanted signal. Signals from voxels which do not differ from the model are suppressed and the resulting filtered low resolution images are transformed back to k-space and combined with the originally acquired peripheral k-space data to form complete, filtered k-space data sets from which images may be reconstructed.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: March 11, 2008
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Walter Block, Arjun Arunachalam
  • Patent number: 7336072
    Abstract: In a method for representation of flow in a magnetic resonance image, a first magnetic resonance image of an examination subject is acquired, wherein the flow occurring in the examination subject is not compensated in a first spatial direction; a second magnetic resonance image is acquired, wherein the flow occurring in the first spatial direction is compensated, the phase of the magnetization in each of the first and the second magnetic resonance images is calculated of the phase difference between the first phase image and the second phase image, which is calculated is a measure for the flow along the first spatial direction. A third magnetic resonance image is acquired, wherein the flow in a second spatial direction perpendicular to the first spatial direction is not compensated, and a fourth magnetic resonance image is acquired, wherein the flow occurring in the second spatial direction is compensated.
    Type: Grant
    Filed: February 24, 2006
    Date of Patent: February 26, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Assmann, Oliver Schreck
  • Patent number: 7333848
    Abstract: A method and system are disclosed for evaluating symptomatic VBD which uses quantitative hemodynamic assessment in order to identify patients at high risk for stroke and provide appropriate guidance for intervention. Patients with symptomatic VBD may be considered for intervention to provide blood flow augmentation if evidence of sufficient flow compromise is present as defined by specific flow criteria, and treated medically otherwise.
    Type: Grant
    Filed: February 2, 2005
    Date of Patent: February 19, 2008
    Assignee: Vassol Inc.
    Inventors: Fady T. Charbel, Fady Charbel, II, Meide Zhao, Anthony Curcio, Sepideh Amin-Hanjani
  • Patent number: 7333846
    Abstract: In a method and a magnetic resonance apparatus for functional imaging, a number of images without and with a designational stimulation of the examination subject are sequentially registered in successive alternation, and an information value that indicates whether the image was registered during a phase with or without stimulation, at least one image-related stimulation value, and at least one image-related evaluation correlation value are obtained and stored for every image.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: February 19, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventor: Oliver Schreck
  • Patent number: 7317940
    Abstract: In a method for automatic determination of the actual speed interval of a flowing medium in flow measurements in magnetic resonance imaging, an overview image (localizer) is acquired displayed on a screen, a scout flow measurement is performed by acquiring an image series during a motion cycle at a pre-determined speed interval in a tissue-area to be measured, the peak speed of the medium in the tissue area to be measured is determined on the basis of the scout flow measurement, an optimized flow measurement is performed by acquiring the same images from the acquired image series on the basis of the determined peak speed, and the speed-resolved tissue area obtained by means of the optimized flow measurement is displayed on the screen.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: January 8, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stefan Assmann
  • Patent number: 7315756
    Abstract: A multi-slice double inversion recovery (DIR) pulse sequence with read out of a signal for imaging successive slices implemented on a magnetic resonance image scanner. In the method, when the DIR pulse sequence is applied before imaging each slice, a slab-selective inversion re-inverts the entire slab that includes all of the slices. All slices are imaged within a predefined repetition time (TR). The number, N, of slices acquired per TR controls the inversion time to execute the read out of the signal for imaging each slice at a zero-crossing point of blood. In a test, multi-slice DIR images of carotid arteries were obtained with N ranging from 2-8, for four subjects. The results were compared with those for both standard single-slice DIR, and inflow saturation techniques. Multi-slice DIR with N=2-6 provided blood flow suppression in carotid arteries similar to that of single-slice DIR, and significantly better than inflow saturation.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: January 1, 2008
    Assignee: University of Washington
    Inventors: Vasily L. Yarnykh, Chun Yuan
  • Patent number: 7313428
    Abstract: The present invention is a technique of, and system for, imaging vascular anatomy over distance considerably greater than the maximum practical field of view of a magnetic resonance imaging system while using substantially one contrast agent injection. The technique and system of the present invention acquires image data of a plurality of image volumes which are representative of different portions of the patient's body. The image data of each image volume includes image data which is representative of the center of k-space. The acquisition of image data which is representative of the center of k-space is correlated with a concentration of contrast agent in the artery(ies) residing in the image volume being substantially greater than the concentration of contrast agent in veins and background tissue adjacent to the artery(ies).
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: December 25, 2007
    Inventors: James F. M. Meaney, Martin R. Prince
  • Patent number: 7308298
    Abstract: A magnetic resonance imaging technique provides adequate MT effects by applying a shortened MT pulse and scan time. An MT pulse whose frequency is off-resonance to a region to be imaged of an object is first applied to he object, a spoiler pulse is applied to the object, and an echo signal is acquired from the region to be imaged. The duration of the MT pulse is set to a relatively shorter time than conventional. Preferably, the duration is less than 10 ms. The area of the MT pulse waveform is set to a specified value equivalent to the conventional. The MT pulse is preferably applicable to a two-dimensional scan using the multislice technique but can also be used in a three-dimensional scan.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: December 11, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Mitsue Miyazaki
  • Patent number: 7298142
    Abstract: A method and apparatus for obtaining a parameter of interest relating to a region proximate a nuclear magnetic resonance (NMR) logging tool suitable for subterranean well logging is disclosed. The nuclei of the region are subjected to a pulsed NMR technique and are productive of NMR logging data, the nuclei of the region characteristically having a longitudinal relaxation time T1 distribution and an apparent transverse relaxation time T2app distribution. In response to the NMR logging data, an R distribution is defined as R=T1/T2app, the T2app and R distributions are processed as separate bins, along with the NMR logging data, according to a two-dimensional inversion model, and a signal intensity map of R versus T2app is provided that is representative of the parameter of interest relating to the region. In response to a high-intensity signal on the map being within a first range of T2app values and a first range of R values, the presence of a light hydrocarbon within the region is identified.
    Type: Grant
    Filed: June 27, 2005
    Date of Patent: November 20, 2007
    Assignee: Baker Hughes Incorporated
    Inventors: Gabor G. Hursan, Songhua Chen
  • Patent number: 7295006
    Abstract: Disclosed are a method and apparatus for accurately measuring nuclear magnetic resonance (NMR) longitudinal axis relaxation time by minimizing the influence of the amount of blood. The method includes applying a first magnetic field MO to a living body portion into which the blood flows magnetizing the blood in a first direction; applying a second magnetic field MZ to at least a portion of the living body portion, to which the first magnetic field MO is applied, magnetizing at least a portion of the blood in a second direction vertical to the first direction;; blocking MZ detecting a signal that is induced as magnetization is returned from the second direction to the first direction; detecting the amount of blood to which the second magnetic field MZ is applied; and calculating the longitudinal axis relaxation time T1 of the blood based on the induced signal and based on the amount of blood.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: November 13, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sergey Potapov, Jong-hwa Won
  • Patent number: 7292032
    Abstract: An automated image processing technique is disclosed that evaluates pixels of a phase-difference image to determine those pixels corresponding to inflowing phase data and background phase data. Phase-difference images are generated from a first acquisition and a second acquisition. Non-zero spatially varying background phase from the phase-difference images that are due to eddy currents induced by flow encoding gradients used to generate the phase-difference images is determined. This non-zero spatially varying background phase is removed from the phase-difference images to determine phase associated with flowing spins and phase associated with stationary spins.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: November 6, 2007
    Assignee: General Electric Company
    Inventor: Jason A. Polzin
  • Publication number: 20070247150
    Abstract: An fMRI study is conducted using a 2D EPI pulse sequence. A separate blood flow navigator pulse sequence is interleaved with the fMRI data acquisition to monitor blood flow in arteries that feed the brain tissue. Information in the blood flow navigator data is used to reduce errors in the fMRI data due to tissue motion caused by pulsatile blood flow. In one embodiment the blood flow navigator information is used to gate the fMRI acquisition and in another embodiment the information is used to retrospectively correct acquired fMRI data.
    Type: Application
    Filed: April 16, 2007
    Publication date: October 25, 2007
    Inventor: Andre van der Kouwe
  • Patent number: 7283862
    Abstract: The present invention includes a method and apparatus to perform rapid multi-slice MR imaging without ECG gating or requiring breath-holding that is capable of renal profusion analysis and angiographic screening. An ungated interleaved pulse sequence is applied in rapid succession, followed by a delay interval. The ungated interleaved pulse sequence is repeatedly played out with the predefined delay interval between each application of the pulse sequence. The resulting images provide not only a series of temporal phases of contrast-enhanced blood uptake for renal profusion analysis, but also provide enough dynamic range to include angiographic screening of the renal arteries.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: October 16, 2007
    Assignee: General Electric Company
    Inventors: Glenn S. Slavin, Thomas K. F. Foo
  • Publication number: 20070222451
    Abstract: An apparatus for shimming the magnetic field generated by a magnet arrangement of a magnetic resonance imaging (MRI) system, has a number of shim devices of substantially similar cross-sectional dimensions, at least some of the shim devices exhibiting differing ferromagnetic characteristics. A structure body has an elongate, tubular channel cross-sectionally dimensioned to serially receive the shim devices in a predetermined sequence to provide a required distribution of the ferromagnetic characteristics in relation to said magnetic field, the channel being of length sufficient to accommodate the shim devices serially in said predetermined sequence. The shim devices are presented at the entrance of the channel in the sequence, and are forced into the channel in the sequence by pressurized fluid directed toward the entrance.
    Type: Application
    Filed: February 22, 2007
    Publication date: September 27, 2007
    Inventors: Stuart Paul Feltham, Matthew Hobbs, Marcel Jan Marie Kruip
  • Patent number: 7268552
    Abstract: A Toroid Cavity Detector (TCD) is provided for implementing nuclear magnetic resonance (NMR) studies of chemical reactions under conditions of high pressures and temperatures. A toroid cavity contains an elongated central conductor extending within the toroid cavity. The toroid cavity and central conductor generate an RF magnetic field for NMR analysis. A flow-through capillary sample container is located within the toroid cavity adjacent to the central conductor to subject a sample material flowing through the capillary to a static magnetic field and to enable NMR spectra to be recorded of the material in the capillary under a temperature and high pressure environment.
    Type: Grant
    Filed: June 21, 2005
    Date of Patent: September 11, 2007
    Assignee: United States of America as represented by the United States Department of Energy
    Inventors: Rex E. Gerald, II, Michael J. Chen, Robert J. Klingler, Jerome W. Rathke, Marc ter Horst
  • Patent number: 7268547
    Abstract: An apparatus and method for compensating for the effect of tool motion in NMR MWD measurements. Signals obtained from a directionally sensitive receiver are compensated for the effects of tool motion. In an alternative embodiment, directional transmitters and receivers are used, with the pulsing of the transmitter controlled by the output of motion sensors. In another embodiment, the transmitters and receivers may be axisymmetric and the received signals are corrected using results of a NMR simulation program that takes account of the recorded motion of the apparatus.
    Type: Grant
    Filed: October 5, 2004
    Date of Patent: September 11, 2007
    Assignee: Baker Hughes Incorporated
    Inventors: Thomas Kruspe, Martin Blanz
  • Patent number: 7265544
    Abstract: A method and device for obtaining an interference free measurement from a flowmeter. The flowmeter includes a measuring tube through which a flowable medium flows through a magnetic field generated by a magnetic arrangement and at least two measuring electrodes for detecting the measurement voltage induced by the flowable medium. The medium gives rise to interference voltages. The electrodes are connected to an interference-voltage eliminating unit by which common-mode interference is first eliminated by differentiation and unequal interference voltages are subsequently eliminated.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: September 4, 2007
    Assignee: ABB patent GmbH
    Inventors: Dieter Keese, Thomas-Fritz Blume, Dirk Steckel
  • Patent number: 7259558
    Abstract: A method of nuclear magnetic resonance (NMR) imaging is proposed for the rapid detection of oscillatory motion of spins or charged particles to generate shear waves or oscillating electrical currents to induce alternating magnetic fields to the object being imaged, subjected to a fast train of radio-frequency (RF) pulses to induce within the sample a steady-state NMR signal. A scan using an NMR imaging system is carried out with a RF repetition time (TR) matched to the externally imposed oscillatory motion. Small oscillatory displacements of spins in combination with imaging gradients or oscillating magnetic fields related to charge motion generating alternating spin phase dispersions during the rf pulse train disturb the steady-state magnetization.
    Type: Grant
    Filed: December 19, 2005
    Date of Patent: August 21, 2007
    Assignee: University of Basel
    Inventors: Oliver Bieri, Klaus Scheffler
  • Patent number: 7256578
    Abstract: A magnetic resonance imaging system includes a high-frequency magnetic field generating unit for generating and applying a high-frequency magnetic field to a subject placed in a static magnetic field, a gradient magnetic field generating unit for generating a gradient magnetic field to be superimposed on the static magnetic field, and a sequencer for controlling the high-frequency magnetic field generating unit and the gradient magnetic field generating unit to acquire, within a specified part of the heartbeat of the subject, MR data that pertains to a plane through which an axis substantially identical to the body axis of the subject in a k-space extends, and to cause the plane to rotate, at every heartbeat, about the axis substantially identical to the body axis.
    Type: Grant
    Filed: March 2, 2007
    Date of Patent: August 14, 2007
    Assignee: Keio University
    Inventor: Koichi Oshio
  • Patent number: 7218104
    Abstract: Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: May 15, 2007
    Inventors: John Clarke, Robert McDermott, Alexander Pines, Andreas Heinz Trabesinger
  • Patent number: 7215119
    Abstract: In a method for dynamic frequency detection of the resonance frequency in magnetic resonance spectroscopy, by measuring navigator signals at the same point in time in each of a number of successive sequence passes, and by comparing the navigator signals, a frequency shift of the resonance frequency is determined on the basis of which the respective individual spectrum obtained from each sequence repetition is corrected with respect to the measured frequency shift.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: May 8, 2007
    Assignee: Siemens Aktiengesellschaft
    Inventors: Gunnar Krüger, Stefan Röll
  • Patent number: 7205763
    Abstract: In a multi-shot method for diffusion-weighted imaging in magnetic resonance tomography, the sampling of the k-matrix in the readout direction ensues in segments, and immediately after acquisition of an image data set by readout of one segment by means of echo signals, a navigation data set is acquired by readout of the middle region of the k-matrix at virtually the same time. A movement-corrected diffusion-weighted MRT image is generated by combining of the image data sets with the corresponding navigation data sets and subsequent Fourier transformation.
    Type: Grant
    Filed: April 13, 2005
    Date of Patent: April 17, 2007
    Assignee: Siemens Aktiengesellschaft
    Inventor: David Andrew Porter
  • Patent number: 7202662
    Abstract: Errors in qualitative phase contrast measurements due to gradient field heterogeneities are reduced by using either a generalized reconstruction algorithm or an approximate reconstruction algorithm. True velocities are calculated using measured velocity information and phase differences, first moments of gradients, and gyromagnetic ratio.
    Type: Grant
    Filed: June 16, 2003
    Date of Patent: April 10, 2007
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Michael Markl, Norbert J. Pelc, Roland Bammer
  • Patent number: 7196517
    Abstract: A method for evaluating formation fluids includes measuring a nuclear magnetic resonance property related to a total volume of the formation fluids, measuring a dielectric property related to an electromagnetic wave travel time, measuring a bulk density, and solving a set of linear response equations representing a reservoir fluid model to determine fractional fluid volumes from the nuclear magnetic resonance property, the dielectric property, and the bulk density.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: March 27, 2007
    Assignee: Schlumberger Technology Corporation
    Inventor: Robert Freedman
  • Patent number: 7197353
    Abstract: A sensitivity encoding method (SENSE) is used to acquire an MR image having a reduced field of view. The number of aliased replicates caused by surrounding object boundaries is calculated for each image pixel location to obtain optimal aliasing artifact suppression without reducing image SNR.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: March 27, 2007
    Assignee: General Electric Company
    Inventors: Kevin F. King, Lisa C. Angelos
  • Patent number: 7187791
    Abstract: For a purpose of improving homogeneity of an image obtained in a self-calibration by a parallel imaging method generally referred to as SENSE (SENSitivity Encoding), sensitivity factors Sn(p) are calculated using an additive image Ab=?|Cn| of complex images Cn obtained by conducting a calibration scan of an entire FOV for phased array coils Coil_n (n=1–N, N?2) (Steps V2, V3). Moreover, sensitivity maps Sn are generated by conducting curve fitting by the method of least squares weighted by the square of a pixel value Ab(p) of the absolute value additive image Ab (Step V4).
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: March 6, 2007
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventor: Yoshikazu Ikezaki
  • Patent number: 7167740
    Abstract: In a measuring space of the object (1), an essential measurement region (41, 61, 71, 81, 111, 131) having a center region of the measuring space and a plurality of peripheral measurement regions (42, 62, 63, 72, 82, 112, 132) which do not have any region overlapped with the essential measurement region are set. Then, the essential measurement region is combined with a selected peripheral portion of the plurality of the peripheral measurement regions to measure in a preceding manner a nuclear magnetic resonance signal from the object as data of the measuring space. The essential measurement region is combined with the peripheral measurement region of the plurality of the peripheral measurement regions which has not been selected in the preceding measuring step to measure a nuclear magnetic resonance signal from the object as data of the measuring space.
    Type: Grant
    Filed: December 3, 2001
    Date of Patent: January 23, 2007
    Assignee: Hitachi Medical Corporation
    Inventors: Takayuki Abe, Shigeru Watanabe, Hirotaka Takeshima
  • Patent number: 7164123
    Abstract: A method for filtering spurious resonances from an NMR dataset comprises the steps of: (a) creating a first, non-oscillating magnetic field of a predetermined field strength across a sample, (b) intermittently exposing the sample to a second, oscillating magnetic field orthogonal to the first to generate an NMR signal, (c) detecting the NMR signal from the sample, (d) adjusting the first magnetic field to a different predetermined field strength and repeating steps (a) to (c), and (d) comparing the detected signals to obtain an NMR dataset from the sample from which spurious resonances have been filtered.
    Type: Grant
    Filed: December 28, 2005
    Date of Patent: January 16, 2007
    Assignee: Rolls-Royce plc
    Inventors: Peter G. Morris, Terry Moore, Paul Anuzis, Kenneth Astley
  • Patent number: 7145334
    Abstract: In a method and MR apparatus for the automatic segmentation of flow images acquired by magnetic resonance tomography for the depiction of tissue or organs traversed with fluid such as blood, at least one phase image of a selected region of the subject is acquired by magnetic resonance tomography, and fluid-traversed regions in the at least one phase image are automatically segmented.
    Type: Grant
    Filed: November 24, 2004
    Date of Patent: December 5, 2006
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Assmann, Martin Requardt, Ingo Schmitjans, Oliver Schreck
  • Patent number: 7141978
    Abstract: An NMR system comprises an NMR probe comprising multiple NMR detection sites. Each of the multiple NMR detection sites comprises a sample holding void and an associated NMR microcoil. The NMR system further comprises a controllable fluid router operative to direct fluid sample to the multiple NMR detection sites.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: November 28, 2006
    Assignee: Protasis Corporation
    Inventors: Tim L. Peck, Dean Olson, Jim Norcross, David Strand, Jonathan Sweedler
  • Patent number: 7116102
    Abstract: Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: October 3, 2006
    Assignee: The Regents of the University of California
    Inventors: John Clarke, Robert McDermott, Alexander Pines, Andreas Heinz Trabesinger
  • Patent number: 7096056
    Abstract: A method for functional magnetic resonance imaging (fMRI) uses steady-state free precession (SSFP) to image changes in blood oxygenation between two time periods. A center frequency of the SSFP sequence is placed between the different resonant frequencies for oxyhemoglobin and deoxyhemoglobin whereby the signals have a phase difference of 180° and tend to cancel. By repeating the SSFP imaging sequence at different times, the difference in the measured signals provides a measure of change in oxyhemoglobin. RF flip angle of the SSFP sequence is chosen to maximize signal level in the frequency range from that of water in the presence of oxyhemoglobin and that of water in the presence of deoxyhemoglobin.
    Type: Grant
    Filed: June 16, 2003
    Date of Patent: August 22, 2006
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Karla L. Miller, John M. Pauly
  • Patent number: 7078897
    Abstract: An MR method and system of determining elements of the apparent diffusion coefficient tensor in a material with plurality of anisotropic structural units that can be too small to be resolved by direct imaging. MR data is acquired with MR system including pulse sequences, the sequences including imaging or spectroscopy pulse sequences with a series of embedded diffusion-sensitizing gradient waveforms with different gradient strength applied to the material. A nonlinear function of a b-value corresponding to the pulse sequence is defined and the acquired MR data is processed according to defined nonlinear function. Images/maps of the components of the tensor of apparent diffusion coefficients, corresponding to anisotropic structural units, based on the processed MR data, are created. A method of evaluating of the geometrical parameters of lung airways is also described.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: July 18, 2006
    Assignee: Washington University
    Inventors: Dmitriy A. Yablonskiy, Alexander L. Sukstanskii, Mark S. Conradi
  • Patent number: 7075297
    Abstract: A method for evaluating formation fluids includes measuring a nuclear magnetic resonance property related to a total volume of the formation fluids, measuring a dielectric property related to an electromagnetic wave travel time, measuring a bulk density, and solving a set of linear response equations representing a reservoir fluid model to determine fractional fluid volumes from the nuclear magnetic resonance property, the dielectric property, and the bulk density.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: July 11, 2006
    Assignee: Schlumberger Technology Corporation
    Inventor: Robert Freedman
  • Patent number: 7053610
    Abstract: Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: May 30, 2006
    Assignee: The Regents of th University of California
    Inventors: John Clarke, Robert McDermott, Alexander Pines, Andreas Heinz Trabesinger
  • Patent number: 7049815
    Abstract: Pulse sequences are applied to a fluid in an earth formation in a static magnetic field having internal gradients. From the received signals, relaxation and diffusion characteristics of the fluid are determined. The determination takes into account the internal field gradients.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: May 23, 2006
    Assignee: Baker Hughes Incorporated
    Inventors: Gregory Itskovich, Arcady Reiderman
  • Patent number: 7049816
    Abstract: A phase contrast image is produced using a 3D projection reconstruction pulse sequence. A high velocity-to-noise image is produced by using a LOW VENC motion encoding gradient. Phase wrap errors caused by high velocity flow is corrected using phase information in a HIGH VENC image produced from highly undersampled data acquired during the same scan.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: May 23, 2006
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Charles A. Mistretta, Kevin Michael Johnson, Tianliang Gu
  • Patent number: 7046004
    Abstract: A method of steady-state free precession MR imaging is provided that includes the steps of: (a) providing a balanced steady-state free precession imaging sequence that includes a plurality of phase encoding steps, wherein each phase encoding step comprises a phase encoding gradient and a slice selection gradient; and (b) acquiring imaging data by performing the plurality of phase encoding steps in sequence, wherein the imaging data is acquired is compensated for one or more effects due to eddy-currents, flow, or motion related artefacts due to the implementation of one or more artefact compensation strategies that consist of (i) “pairing” of consecutive phase encoding steps and of (ii) “through slice equilibration” of eddy-current and motion or flow related signal oscillations.
    Type: Grant
    Filed: May 6, 2005
    Date of Patent: May 16, 2006
    Assignee: University of Basel
    Inventors: Oliver Bieri, Klaus Scheffler
  • Patent number: 7047062
    Abstract: Disclosed herein is a system and method for decreasing gradient field pulse sequence duration and reducing peripheral nerve stimulation with known gradient pulse areas for a magnetic resonance imaging system. The method comprising: receiving a first desired area corresponding to a first pulse; obtaining a second desired area corresponding to a second pulse; selecting the first pulse as a nested pulse if the first desired area is smaller than the second desired area, and establishing the second pulse as a nesting pulse, otherwise selecting the second pulse as the nested pulse and establishing the first pulse as the nesting pulse. The method also includes: determining an amplitude and pulse duration for the nested pulse and ascertaining an amplitude and pulse duration for the nesting pulse. Finally, the method includes arranging a plurality of gradient field pulse sequences to include the nested pulse and the nesting pulse.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: May 16, 2006
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventors: Paul E. Licato, Steven Wolff
  • Patent number: 7009393
    Abstract: The invention relates to a nuclear magnetic resonance method of detecting and monitoring the flocculation kinetics of high molecular weight fractions of a complex fluid. The inventive method applies the following to the fluid: a first static polarization magnetic field and, subsequently, at least a second oscillating pulsed magnetic field which generates a nuclear magnetic resonance for the nuclei considered and the acquisition of relaxation signals from the nuclei in the fluid. Moreover, the method detects, in the relaxation signals, a first part P1 which is representative of the relaxation of the flocculated fractions in the fluid and a second part P2 which is representative of the relaxation of the liquid fraction of the fluid; and determines the flocculation rate of the fractions by comparison with values M<sb>x</sb>(t=0) and M<sb>x1</sb>(t=0) which were extrapolated at the start of the acquisition times of the two parts.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: March 7, 2006
    Assignee: Institut Francais du Petrole
    Inventors: Jean-Pierre Cohen Addad, Marc Fleury
  • Patent number: 7003343
    Abstract: Current bolus chase magnetic resonance angiography is limited by the imaging time for each station. Tailoring the density of k-space sampling along the anterior-posterior direction of the coronal station allows a substantial decrease in scan time that leads to greater contrast bolus sharing among stations and consequently a significant improvement in image quality. Fast arterial-venous transit in the carotid arteries requires accurate, reliable timing of the acquisition to the bolus transit to maximize arterial signal and minimize venous artifacts. The rising edge of the bolus is not utilized in conventional elliptical-centric view ordering because the critical k-space center must be acquired with full arterial enhancement. The invention provides a recessed elliptical-centric view ordering scheme is introduced in which the k-space center is acquired a few seconds following scan initiation. The recessed view ordering is shown to be more robust to timing errors in a patient studies.
    Type: Grant
    Filed: April 1, 2002
    Date of Patent: February 21, 2006
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Richard Watts, Yi Wang, Martin R. Prince
  • Patent number: 6995560
    Abstract: A method of chemical species suppression for MRI imaging of a scanned object region including acquiring K space data at a first TE, acquiring K space data at a second TE, reconstructing images having off resonance effects, estimating off resonance effects at locations throughout the reconstructed image, and determining the first and second chemical species signals at image locations of the scanned object from the acquired signals and correcting for blurring resulting from off resonance effects due to B0 inhomogeneity.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: February 7, 2006
    Inventors: Jeffrey L. Duerk, Jonathan S. Lewin, Hisamoto Moriguchi
  • Patent number: 6992483
    Abstract: The present invention provides a system and method of removing heat from an MR imaging device while maintaining internal and external temperatures below maximum operating limits, thereby enabling higher power applications for faster imaging with improved image quality as well as, allowing longer scan times for interventional procedures. The system includes a vacuum chamber housing the gradient coils and a vacuum pump connected thereto to regulate the pressure and humidity within the chamber. A heat exchanger, coolant pump, and controller are provided to regulate the temperature of coolant designed to dissipate heat from the gradient coils in response to at least one temperature sensor.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: January 31, 2006
    Assignee: General Electric Company
    Inventors: Pierre R. Emeric, Carl R. Hedlund
  • Patent number: 6987997
    Abstract: A technique is set forth for MR spectroscopy that is capable of reducing signal overlap between metabolite signals for improved clinical analysis of metabolite content. The technique includes varying an echo time across a scanning dimension. Once a span of echo time for an acquisition dimension is determined, and the number of acquisition data points is known, a variance between echo times can be determined. A pulse sequence with differing echo times is then applied for each frame, and after data is acquired, an image is reconstructed that significantly improves metabolite signal separation.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: January 17, 2006
    Assignee: General Electric Company
    Inventors: Ralph E. Hurd, Napapon Sailasuta
  • Patent number: 6985766
    Abstract: The invention refers to an apparatus for positioning medical treatment devices or treatment supporting devices (2) by a transportation means (1) to move said devices (2) to a predetermined position, said transportation means (1) including an automatically guided transport system (3, 7), and to a corresponding method and the use of an automatically guided transport system to perform said positioning tasks.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: January 10, 2006
    Assignee: BrainLAB AG
    Inventors: Richard Braun, Robert Schmidt
  • Patent number: 6980845
    Abstract: This invention is a method for multi-slice CBF imaging using continuous arterial spin labeling (CASL) with an amplitude modulated control which is both highly effective at controlling for off resonance effects, and efficient at doubly inverting inflow spins, thus retaining the signal advantages of CASL versus pulsed ASL techniques.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: December 27, 2005
    Assignee: The Trustees Of The University Of Pennsylvania
    Inventor: David C. Alsop
  • Patent number: 6972564
    Abstract: An objective oriented NMR logging method selects pulse sequences over a plurality of frequencies from a set of building blocks. The building blocks include trainlet sequences wherein each trainlet comprises an excitation pulse and a plurality of refocusing pulses, the total length of a trainlet being typically less than 10 ms. Another building block is a short CPMG or modified CPMG sequence and yet another building block is a regular CPMG or modified CPMG sequence. The modified CPMG sequences may have refocusing pulses with a tipping angle less than 180° to reduce the power consumption. Based on the logging objective (formation evaluation or FE, FE plus hydrocarbon typing, FE plus gas evaluation) the building blocks are combined at a plurality of frequencies with different wait times and TEs.
    Type: Grant
    Filed: November 5, 2002
    Date of Patent: December 6, 2005
    Assignee: Baker Hughes Incorporated
    Inventors: Songhua Chen, Carl M. Edwards
  • Patent number: 6963199
    Abstract: A rare gas polarizer apparatus includes a polarizing section for bringing a rare gas contained in a mixed gas to a hyperpolarized state, an extracting section for sublimating the rare gas from the mixed gas, extracting the rare gas as a solid, and vaporizing the extracted solid rare gas, and a supplying section for mixing the vaporized rare gas with an inspired material, and supplying the gas to a mask section that is closed against the outer air and covering the respiratory organs of the subject.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: November 8, 2005
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventor: Hiroshi Sato
  • Patent number: 6958605
    Abstract: A method and system of correcting for a motion of an object are provided. In these system and method, the navigator data and map data are first obtained for the object. Then, the navigator data is compared with the map data to generate comparison data. Thereafter, a translation and/or a rotation of the object is corrected in real time as a function of the comparison data. The navigator can be preferably an octant navigator and/or a clover leaf navigator. In one exemplary embodiment, a scanning sequence can be used to determine a position of the object. This scanning sequence may include a signal portion which includes at least one radio frequency signal, a navigator portion which includes at least one octant navigator or one clover leaf navigator, and a spoiler portion provided for reducing a signal magnitude of the scanning sequence. The navigator is provided for allowing a measurement of at least one of the rotation and translation of the object.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: October 25, 2005
    Assignee: The General Hospital Corporation
    Inventors: Anders M. Dale, Andre J. W. Van Der Kouwe