Patents by Inventor Andreas Greiser

Andreas Greiser has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9101283
    Abstract: In a method and magnetic resonance system to determine a flow coding for a flow measurement with the magnetic resonance system, in order to determine the optimal flow coding, a flow pre-measurement with multiple different flow codings is conducted within a slice within a body to be examined, each of these codings allowing flow velocities to be detected with a sensitivity dependent on the respective coding. A velocity distribution of the non-slice-location-specific flow velocity values is generated from all of the results of this flow pre-measurement by a common Fourier transformation. The optimal flow coding for the flow measurement is then determined based on this velocity distribution.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: August 11, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: Andreas Greiser
  • Publication number: 20150070015
    Abstract: In a method and apparatus for magnetic resonance imaging, in order to create a T1 map, an pulse sequence is used that includes at least one exposure cycle, wherein the exposure cycle includes an inversion pulse, a saturation pulse quantity of one or more saturation pulses and a readout step quantity of one or more readout steps. Within the exposure cycle, at least one saturation pulse of the saturation pulse quantity follows the inversion pulse and at least one readout step of the readout step quantity follows the at least one saturation pulse.
    Type: Application
    Filed: September 12, 2014
    Publication date: March 12, 2015
    Applicant: Siemens Aktiengesellschaft
    Inventor: Andreas Greiser
  • Patent number: 8975893
    Abstract: In a method for optimization of a flow coding with switching of an additional bipolar dephasing gradient pair, used in a magnetic resonance (MR) phase contrast angiography, the strength of the flow coding is selected depending on the flow velocity in the vessels that should be depicted. MR signals of an examination region are acquired with continuously running overview measurements, with an operator-selected flow coding strength. After the selected flow coding strength is adopted automatically for the next measurement of the continuously running overview measurements, and two partial measurements with different flow codings are implemented for each selected strength and a phase difference image from the two partial measurements is calculated and depicted in real time, and the selected flow coding strength is automatically adopted for the MR phase contrast angiography.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: March 10, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventors: Andreas Greiser, Peter Speier
  • Publication number: 20150061671
    Abstract: MR signals are acquired with a method for phase contrast magnetic resonance (MR) imaging with speed encoding, in order to acquire raw data for multiple MR images. The multiple MR images are reconstructed. For this purpose, matrix elements are determined for numerous matrices, wherein the sum of the numerous matrices results in a pixel matrix. The pixel matrix has matrix elements that represent the pixel values for a reference MR image with flow compensation. The pixel matrix has further matrix elements that represent the pixel values for the at least one MR image with speed encoding. The matrix elements of the numerous matrices are determined such that a first matrix of the numerous matrices fulfills a first condition.
    Type: Application
    Filed: August 29, 2014
    Publication date: March 5, 2015
    Applicant: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Andreas Greiser, Jana Hutter, Peter Schmitt
  • Patent number: 8957682
    Abstract: In a method and a magnetic resonance system to automatically determine parameters of a phase contrast flow measurement, a phase contrast pre-measurement with a flow coding sequence is implemented in a predetermined volume segment of an examination subject, and the flow coding sequence is varied in terms of its parameters so that a pre-measurement is respectively implemented for multiple different parameter sets of the flow coding sequence. A model is automatically determined with which a dimension of a phase error can be determined for each parameter set in the flow measurement, in that phase values of the pre-measurement which is implemented with the flow coding sequence with the respective parameter set are analyzed. Those parameters of the flow measurement at which the dimension of the phase error is smallest are automatically determined.
    Type: Grant
    Filed: March 2, 2012
    Date of Patent: February 17, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: Andreas Greiser
  • Publication number: 20140348406
    Abstract: In a method and a magnetic resonance tomography system, at least two temporally separate original data sets are acquired with one phase measurement value being acquired for each pixel in each original image data set. An optimization technique for the shared calculation of corrected phase values for the pixels in the data sets is implemented in a computer, wherein the corrected phase values of the pixels in a first of the data sets is in each case dependent at least on the phase measured value of the pixel at the same location in a second of the data sets which is recorded beforehand or afterwards, and the corrected phase values of the pixels in the second data set are in each case dependent at least on the phase measured value of the pixel at the same place in the first data set. Corrected image data sets are generated from the corrected phase values.
    Type: Application
    Filed: May 21, 2014
    Publication date: November 27, 2014
    Applicant: Siemens Aktiengesellschaft
    Inventors: Brett Cowan, Andreas Greiser, Arne Littmann, Alistair Young
  • Publication number: 20140314289
    Abstract: A computer-implemented method for determining magnetic field inversion time of a tissue species includes generating a T1-mapping image of a tissue of interest, the T1-mapping image comprising a plurality of T1 values within an expected range of T1 values for the tissue of interest. An image mask is created based on predetermined identification information about the tissue of interest. Next, an updated image mask is created based on a largest connected region in the image mask. The updated image mask is applied to the T1-mapping image to yield a masked image. Then, a mean relaxation time value is determined for the largest connected region. The mean relaxation time value is then used to determine a time point for nulling longitudinal magnetization.
    Type: Application
    Filed: April 4, 2014
    Publication date: October 23, 2014
    Applicant: The United States of America, as represented by the Secretary, Dept of Health and Human Services
    Inventors: Bruce S. Spottiswoode, Xiaoguang Lu, Xiaoming Bi, Hui Xue, Christopher Glielmi, Peter Kellman, Andreas Greiser
  • Patent number: 8848990
    Abstract: A method for performing motion compensation in a series of magnetic resonance (MR) images includes acquiring a set of MR image frames spanning different points along an MR recovery curve. A motion-free synthetic image is generated for each of the acquired MR image frames using prior knowledge pertaining to an MR recovery curve. Each of the acquired MR images is registered to its corresponding generated synthetic images. Motion within each of the acquired MR image is corrected based on its corresponding generated synthetic image that has been registered thereto.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: September 30, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hui Xue, Saurabh Shah, Jens Gühring, Andreas Greiser, Christophe Chefd'hotel, Christoph Guetter, Marie-Pierre Jolly, Sven Zuehlsdorff
  • Patent number: 8798942
    Abstract: In a method and a device for phase-sensitive flow measurement of a volume segment of an examination subject in a measurement system, the volume segment is divided into multiple partial volume segments and the following steps are executed repeatedly until the volume segment has been completely measured: movement of a table such that a center of one of the partial volume segments to be measured essentially corresponds to the isocenter of the magnetic resonance system, and implementation of the phase-sensitive flow measurement for the partial volume segment to be measured while the center of the partial volume segment essentially corresponds to the isocenter.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: August 5, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Andreas Greiser, Edgar Mueller, Michael Zenge
  • Publication number: 20140084916
    Abstract: In a method and magnetic resonance (MR) system to generate an MR phase contrast angiography image of an examination subject, velocity-dependent phase information is impressed on moving spins in the examination subject by switching additional bipolar coding gradients that are in addition to the basic phase coding and readout gradients. For the creation of the MR phase contrast angiography images, the MR signals of the examination subject are read out in raw data space with a non-Cartesian acquisition pattern during a readout gradient. The additional bipolar coding gradients switched such that they proceed along a coordinate system that corresponds to the non-Cartesian acquisition pattern, and such that a coordinate axis of this coordinate system proceed along the readout gradient.
    Type: Application
    Filed: September 25, 2013
    Publication date: March 27, 2014
    Inventors: Andreas Greiser, Peter Schmitt
  • Patent number: 8675940
    Abstract: A method of deriving blood flow parameters from a moving three-dimensional (3D) model of a blood vessel includes determining a reference vascular cross-sectional plane through a location of a lumen in a moving 3D model of the blood vessel at one time within the model, determining a plurality of target vascular cross-sectional planes at multiple times via temporal tracking of the reference plane based on a displacement field, determining a plurality of contours based on an intersection of the target vascular cross-sectional planes with the moving 3D vessel model at multiple times within the model, and determining a blood flow parameter of the vessel from intersections of each contour of a given one of the times with a phase contrast magnetic resonance (PC-MRI) image of the blood vessel from the corresponding time.
    Type: Grant
    Filed: October 26, 2010
    Date of Patent: March 18, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Mehmet Akif Gulsun, Andreas Greiser, Jens Guehring, Arne Littmann, Edgar Müller
  • Publication number: 20140062481
    Abstract: In MR imaging of a predetermined volume segment of a living examination subject, the examination subject is stimulated with a defined stimulation pattern, MR data of the predetermined volume segment, are acquired, and MR images based on the MR data are generated that depend on the stimulation pattern. The predetermined volume segment is an internal organ or muscle tissue of the examination subject.
    Type: Application
    Filed: September 5, 2013
    Publication date: March 6, 2014
    Inventors: Andreas Greiser, Jens Guehring, Randall Kroeker, Edgar Mueller, Manuela Rick, Michaela Schmidt, Aurelien Stalder
  • Patent number: 8581583
    Abstract: In a method and apparatus for MR imaging, a data acquisition sequence is executed wherein at least two slices of an examination subject are imaged in parallel with a gradient echo method for spatially resolved quantification of the T1 relaxation time. At least one first acquisition sequence is implemented to acquire MR data from a first slice of the examination subject and at least one second acquisition sequence is implemented to acquire MR data from a second slice of the examination subject. The acquisition sequences each include an inversion pulse and at least two successive readout steps. The first and second acquisition sequences are temporally offset from one another such that they at least partially overlap.
    Type: Grant
    Filed: January 21, 2011
    Date of Patent: November 12, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventor: Andreas Greiser
  • Patent number: 8570039
    Abstract: In a method and a device for phase-sensitive flow measurement of a volume segment of an examination subject using a magnetic resonance (MR) system, the volume segment is coded for imaging of this volume segment and a phase coding of the volume segment to code flow information of the volume segment is implemented. MR data are read out from the volume segment and the MR data are evaluated in order to generate an image of the volume segment with flow information. The phase coding to code the flow information is thereby independent of gradients which are used for spatial coding of the volume segment.
    Type: Grant
    Filed: December 10, 2010
    Date of Patent: October 29, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventor: Andreas Greiser
  • Publication number: 20130278259
    Abstract: In a method for a rapid determination of spatially resolved magnetic resonance relaxation parameters in an area of examination, a preparation pulse is radiated into the area of examination. During the relaxation of the longitudinal magnetization, spatially encoded magnetic resonance signals are acquired at a minimum of two different points in time using a fast magnetic resonance sequence. At each inversion time, an image data record is reconstructed from the magnetic resonance signals, which are elastically registered to each other. From the recorded image data records, values of magnetic resonance relaxation parameters are spatially accurately determined.
    Type: Application
    Filed: April 19, 2013
    Publication date: October 24, 2013
    Inventors: Andreas Greiser, Peter Schmitt, Hui Xue
  • Publication number: 20130272591
    Abstract: Phase sensitive T1 mapping is provided in magnetic resonance (MR). The phase from samples of a modified Look-Locker inversion recovery sequence may be used to normalize contrast, allowing for accurate motion registration without extra information acquisition. The sign may be estimated, allowing T1 mapping with a single application of a non-linear fit.
    Type: Application
    Filed: April 17, 2013
    Publication date: October 17, 2013
    Applicants: SIEMENS CORPORATION, NATIONAL INSTITUTES OF HEALTH, SIEMENS AKTIENGESELLSCHAFT
    Inventors: Hui Xue, Peter Kellman, Andreas Greiser
  • Patent number: 8466677
    Abstract: In a magnetic resonance (MR) device and method to determine a background phase curve in MR image data, in first MR image data and in second MR image data that respectively represent different segments (for example different slices) of an examination subject, first and second pixels are identified that represent essentially stationary tissue, and the associated phase values are determined. Phase correction values for the first MR image data are determined depending on the phase values determined for the first and second pixels that represent essentially stationary tissue.
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: June 18, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventors: Andreas Greiser, Arne Littmann
  • Publication number: 20130060126
    Abstract: For the generation of a magnetic resonance (MR) image of a predetermined volume segment of a living subject, a tracking factor is determined for each of different regions of the volume segment, from which the position of the respective region can be determined depending on a position of a moving area of the subject. MR image data of the volume segment are acquired for different positions of the moving area. The position of the moving area is calculated depending on the position and the tracking factor of the respective region, and the MR image data of the respective region are reconstructed using the MR image data of the volume segment corresponding to the calculated position of the moving area. The MR image of the predetermined volume segment is generated as a combination of the constructed MR image data of the regions.
    Type: Application
    Filed: March 2, 2012
    Publication date: March 7, 2013
    Inventor: Andreas Greiser
  • Patent number: 8379946
    Abstract: In a method of a magnetic resonance system and a method and computer-readable storage medium for the operation thereof to acquire magnetic resonance image data of an examination subject, wherein magnetic resonance system has a number of subsystems and a control device, a number of adjustment measurements to adjust at least one subsystem for making a medical diagnostic data acquisition are implemented through the control device. In these adjustment measurements, an adjustment volume associated with the appertaining adjustment measurement is taken into account that encompasses at least one region of a body containing the examination subject. For this purpose, markings established by the control device within image data of the examination subject and characterizing the spatial occupation (position and orientation) and/or a dimension of the examination subject are determined.
    Type: Grant
    Filed: May 5, 2010
    Date of Patent: February 19, 2013
    Assignees: Siemens Aktiengesellschaft, Siemens Medical Solutions USA, Inc.
    Inventors: Andreas Greiser, Saurabh Shah
  • Patent number: 8346341
    Abstract: A method for determining an item of positioning information for ECG electrodes during an examination with a magnetic resonance facility is provided. An image data record of a region surrounding the heart of a patient and the electrodes arranged on the surface of the patient is recorded. A position of the longitudinal heart axis and a position of the electrodes in the image data record are determined. A target position suited to determining evaluable ECG signals is automatically calculated for each of the electrodes by considering the position of the longitudinal heart axis and a displacement from the position of the electrodes to the target position. An item of positioning information for the electrodes is displayed by taking the displacements into consideration.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: January 1, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventor: Andreas Greiser