Abstract: An MRI scanner and an MRI method that effectively reduce the inherent difference in timing of TE in the SIR images by using alternating polarity of the slice selective gradient pulse Gs and corresponding alternate polarity in RF phase offset in the excitation pulse. By using alternating polarity selective gradients, the refocusing gradient pulse on the Gs axis can be eliminated between the excitation pulses so that the time spacing between the multiple SIR excitation pulses is reduced, and therefore the time delay between onset of slice signal decay is reduced. This results in an earlier possible TE of the first excited slice, hence less signal decay and higher SNR, and overall the TE of different slices can be more nearly the same.
Abstract: A cooling device for disposal between two flat coils of a gradient coil has at least one first and with at least one second foil that are connected to each other in areas such that continuous cooling channels for a cooling fluid are formed. The cooling channels are branched, whereby an improved cooling effect is produced with a smaller thickness of the cooling device.
Type:
Grant
Filed:
September 24, 2012
Date of Patent:
October 18, 2016
Assignee:
SIEMENS AKTIENGESELLSCHAFT
Inventors:
Norbert Huber, Lothar Schoen, Stefan Stocker, Muris Torlak
Abstract: A nuclear magnetic resonance relaxation dispersion method to determine the wettability and other parameters of a fluid in a porous medium such as in an earth formation is provided. The method includes the steps of measuring the spin-lattice relaxation time T1 of the fluid in the porous medium at varying polarizing magnetic field strengths or nuclear Larmor frequencies; and determining whether the values of T1 at varying Larmor frequencies follow a dispersion curve that is characteristic of the parameter of the fluid in the porous medium to be determined.
Type:
Grant
Filed:
July 7, 2009
Date of Patent:
October 4, 2016
Assignee:
SCLUMBERGER TECHNOLOGY CORPORATION
Inventors:
Jean-pierre Korb, Gabriel Freiman, Benjamin Nicot, Patrice Ligneul
Abstract: In a method and apparatus for magnetic resonance (MR) imaging, a magnetization of nuclear spins in a subject is prepared in multiple preparation modules of an acquisition sequence. MR signals are acquired with at least one imaging module of the sequence. Spoiler gradient fields are generated in the multiple preparation modules in order to affect a transverse magnetization of the spins. The spoiler gradient fields that are applied in at least two different preparation modules are spatially varied along different directions. Spoiler gradient moments of the spoiler gradient fields are selected so that, for at least one of three orthogonal spatial directions, a weighted sum of the spoiler gradient moments that are applied along this spatial direction satisfies a threshold condition.
Abstract: A medical imaging apparatus includes a first imaging modality which is formed by a magnetic resonance apparatus and which comprises a cylindrical gradient coil unit, and a further imaging modality which comprises a detector unit. The detector unit of the further imaging modality is supported in a radial direction within an area surrounded by the gradient coil unit and an annular gap is disposed between the detector unit of the further imaging modality and the gradient coil unit. The further imaging modality includes a pressure unit which is disposed in the annular gap between the detector unit of the further imaging modality and the gradient coil unit.
Abstract: A computer-implemented method for learning a tight frame includes acquiring undersampled k-space data over a time period using an interleaved process. An average of the undersampled k-space data is determined and a reference image is generated based on the average of the undersampled k-space data. Next, a tight frame operator is determined based on the reference image. Then, a reconstructed image data is generated from the undersampled k-space data via a sparse reconstruction which utilizes the tight frame operator.
Type:
Grant
Filed:
September 16, 2013
Date of Patent:
September 27, 2016
Assignee:
Siemens Aktiengesellschaft
Inventors:
Jun Liu, Qiu Wang, Mariappan Nadar, Michael Zenge, Edgar Mueller
Abstract: Regardless of the measurement conditions, the degradation of the image quality due to a vibrational error magnetic field, which is generated by the vibration of the mechanical structure of an MRI apparatus, is reduced. In order to do so, error magnetic field image data indicating an error magnetic field distribution is acquired on the basis of an echo signal measured using a pulse sequence having a test gradient magnetic field, a parameter value of a damped vibration function showing a vibrational error magnetic field is calculated using the error magnetic field image data, and a correction magnetic field is calculated on the basis of the calculated parameter value of the damped vibration function showing the vibrational error magnetic field.
Abstract: Systems, methods, and apparatus for magnetic induction tomography imaging of specimens, such as human tissue specimens, using a single coil are provided. A plurality of coil property measurements can be obtained using the single coil at a plurality of discrete locations relative to the specimen. The single coil can be designed to be relatively easy to be placed in many different positions/orientations relative to the specimen. A three-dimensional electromagnetic property map, such as a three-dimensional conductivity map or a three-dimensional permittivity map, can be generated from the plurality of coil property measurements obtained using the single coil by accessing a model correlating coil property measurements obtained by the single coil with an electromagnetic property distribution of the specimen.
Type:
Grant
Filed:
February 27, 2014
Date of Patent:
September 13, 2016
Assignee:
Kimberly-Clark Worldwide, Inc.
Inventors:
Joseph R. Feldkamp, Shawn Jeffery Sullivan
Abstract: A magnetic resonance imaging apparatus configured to carry out a pulse sequence in synchronization with a biosignal is provided. The pulse sequence includes an RF pulse, and a data acquisition sequence for acquiring data when a wait time has passed after the RF pulse, wherein the wait time has a variable value that can be varied based on the biosignal.
Abstract: A method for analyzing wine proposes puncturing the closure (60) of a wine bottle (61) containing wine (62) with a disposable cannula (3) having a lateral cannula opening (32) and a female Luer connection (30), and filling a disposable syringe (4) having a male Luer connection (41) with an inert gas. At least part (69) of the wine sample (65) is transferred into an analytical spectrometer (68) and spectrometric analysis of the wine sample (65) is carried out. An inexpensive method is thereby proposed that is easy to perform for analyzing a wine sample from a sealed wine bottle without impairing the quality or storage stability of the wine remaining in the wine bottle due to withdrawal of a wine sample from the wine bottle, in particular, wherein the volume of the removed wine sample can be easily controlled.
Abstract: The present invention relates to a magnetic resonance imaging system comprising a main magnet (102), the main magnet (102) comprising a magnet bore, the bore having a longitudinal axis (118) parallel to the main magnetic field of the main magnet (102), the magnet bore comprising a gradient coil system, wherein the gradient coil system comprises a first (108) satellite coil and an inner coil (114), wherein the first satellite coil comprises at least one pair of saddle coils (200; 202; 204; 206) arranged oppositely over the magnet bore and wherein the inner coil (114) comprises at least two pairs of saddle coils (208) arranged oppositely over the magnet bore, wherein the inner coil (114) is located at a larger diameter from the central axis (118) than the first (108) satellite coil, wherein the first satellite coil and the inner coil form a stepped coil structure.
Type:
Grant
Filed:
December 2, 2009
Date of Patent:
September 6, 2016
Assignee:
Koninklijke Philips N.V.
Inventors:
Jan Konijn, Gerardus Bernardus Jozef Mulder
Abstract: A magnetic resonance imaging (MRI) system includes a split magnet system having a pair of MRI magnet housings separated by gap. A pair of main MRI magnets are disposed within respective MRI magnet housings. A plurality of buttress assemblies are attached to the MRI magnet housings. Some or all of the buttress assemblies are provided with removable connections to the MRI magnet housings. This allows for partial disassembly of the MRI system for improved transport and maneuverability for relocating the MRI system. The MRI system can include a gantry in the gap for supporting a radiation therapy system. Also, the removably buttress assemblies can be used for housing conduits, such as electrical and fluid conduits, between the pair of MRI magnet housings.
Type:
Grant
Filed:
August 5, 2014
Date of Patent:
August 23, 2016
Assignee:
ViewRay Technologies, Inc.
Inventors:
James F. Dempsey, John L. Patrick, Shmaryu M. Shvartsman, Gordon D. DeMeester
Abstract: A method for reconstructing a plurality of images depicting a subject from image data that is simultaneously acquired from a corresponding plurality of slice locations with a magnetic resonance imaging (MRI] system is provided. Image data is acquired following the application of radio frequency (RF] energy to the plurality of slice locations. The RF energy is tailored to provide a different phase to each of the plurality of slice locations. Reference image data is also acquired for each slice location following the application of RF energy that has the same phase as is used to excite the respective slice location for the acquisition of the image data. Aliased images are reconstructed from the image data, and reference images are reconstructed from the reference image data. Using both of these image sets, an unaliased image is produced for each of the plurality of slice locations.
Type:
Grant
Filed:
February 25, 2011
Date of Patent:
August 16, 2016
Assignee:
The Medical College of Wisconsin, Inc.
Inventors:
Andrzej Jesmanowicz, Shi-Jiang Li, James S. Hyde
Abstract: A magnetic resonance imaging (MRI) is configured to effect magnetic resonance angiography (MRA) data acquisition sequences including electrocardiogram (ECG) triggered fresh blood imaging (FBI) images respectively associated with systolic and diastolic phases of ECG cycles. An operator input and display interface may be configured to provide operator options for independently controlling at least one imaging sequence parameter to have a different value for each of systolic and diastolic phase images in an FBI MRI data acquisition sequence.
Abstract: A method and magnetic resonance tomography system to generate magnetic resonance image data of an examination subject, raw imaging data are acquired from multiple slices of a predetermined volume region of the examination subject using local coils during a table feed in the magnetic resonance scanner. Image data of the slices are reconstructed on the basis of the raw imaging data. A normalization of the image data is subsequently implemented on the basis of measured coil sensitivity data of the local coils that are used.
Abstract: In a nuclear magnetic resonance (NMR) spectrometer, a sample spins about an axis tilted at a magic angle, a corrective magnetic field generating portion produces a corrective magnetic field, and a control portion controls the operation of the corrective magnetic field generating portion. An arithmetic unit included in the control portion uses at least one of BZ(1), B1(1)e, and B1(1)o or the linear sum of at least two of them as the first-order magnetic field component of the corrective magnetic field, uses at least one of B2(2)e, B2(2)o, B2(1)e, and B2(1)o or the linear sum of at least two of them as the second-order magnetic field component of the corrective magnetic field, and uses at least one of BZ(3), B3(1)e, B3(1)o, B3(2)e, B3(2)o, B3(3)e, and B3(3)o or the linear sum of at least two of them as the third-order magnetic field component of the corrective magnetic field.
Abstract: In one embodiment, a system includes a gradient coil driver configured to supply electrical signals to a gradient coil of a magnetic resonance imaging system. The gradient coil driver includes an electronic circuit. The electronic circuit includes a first H-bridge circuit electrically coupled to a power source. The first H-bridge includes a plurality of metal-oxide-semiconductor field-effect transistor (MOSFET) switches; and a plurality of diodes electrically coupled in parallel with each MOSFET switch. Each diode of the plurality of diodes is configured to conduct current to cause zero voltage potential across a source and a drain of one of the plurality of MOSFET switches. The first H-bridge also includes a load configured to regulate currents flowing through each of the plurality of diodes and each MOSFET switch of the plurality of MOSFET switches.
Type:
Grant
Filed:
September 14, 2012
Date of Patent:
July 12, 2016
Assignee:
General Electric Company
Inventors:
Juan Antonio Sabate, Rixin Lai, Lei Wang
Abstract: A Nuclear Magnetic Resonance (NMR) apparatus and method for measuring the water content of samples has a device to produce a main magnetic field; a sample receiving space within a main magnetic field; a device to excite a measurable RF magnetization to a sample placed into the sample receiving space at an operating frequency defined by the main magnetic field; a device to measure the RF signal produced by the excited sample; and a device to determine the water content in the sample based on the RF signal. The sample receiving space is capable of accommodating a sample having a volume of at least 0.5 dm3, and the device to produce a main magnetic field has a resistive electromagnet which is adapted to produce a main magnetic field corresponding to an operating frequency of 400-2000 kHz.
Abstract: A method to compensate for the magnetic field heterogeneity inside an object of investigation in a MR device obtains an uncorrected magnetic field distribution of the object and executes an MR sequence with a desired k-space coverage by applying RF pulses to generate a transverse magnetization within the object. MR signal data is recorded, magnetic field shimming parameters are dynamically updated and MR signal data are reconstructed to produce images or localized spectroscopic data. Artifacts in a reconstructed image resulting from an uncorrected magnetic field distribution are suppressed by temporally separating MR signals originating from at least two different sub-volumes within a volume of transverse magnetization by generating a nonlinear phase distribution within the object and by dynamically updating shimming parameters to compensate for the field inhomogeneity distributions within the different sub-volumes in the volume of transverse magnetization.
Type:
Grant
Filed:
March 8, 2012
Date of Patent:
June 28, 2016
Assignee:
UNIVERSITAETSKLINIKUM FREIBURG
Inventors:
Walter Witschey, Maxim Zaitsev, Jürgen Hennig, Gerrit Schultz, Daniel Gallichan