Patents by Inventor Alto Stemmer

Alto Stemmer 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).

  • Publication number: 20210181285
    Abstract: In a method for activating a magnetic resonance imaging (MRI) system for generating MRI data relating to an examination subject, in which system raw magnetic resonance (MR) data is captured, having at least one spin echo or turbo spin echo pulse sequence: a radio frequency (RF) excitation pulse is emitted to excite a region that contains a region to be imaged, the excited region being defined by a selection gradient; an RF refocusing pulse is emitted to influence a refocusing region, the refocusing region at least partly including the region to be imaged, and being defined by at least one selection gradient; and high-frequency (HF) signals are received to acquire raw MR data. A spatial extent of the excitation region is selected to be different (e.g. significantly different) from a spatial extent of the refocusing region.
    Type: Application
    Filed: December 16, 2020
    Publication date: June 17, 2021
    Applicant: Siemens Healthcare GmbH
    Inventor: Alto Stemmer
  • Patent number: 11035921
    Abstract: In a method for operating a magnetic resonance (MR) facility during recording of MR data by using a MR sequence including a saturation module for a spin type to be saturated, in which a high-frequency saturation pulse is emitted between first and second spoiler gradient pulses, and multiple further gradient pulses apart from the spoiler gradient pulses, eddy current data is determined. The eddy current data describes eddy currents existing during emission of the saturation pulse and resulting from the further gradient pulses. Further, a pulse parameter of the first spoiler gradient pulse is selected based on the eddy current data such that the eddy currents generated by the first spoiler gradient pulse compensate for at least part of the eddy currents described by the eddy current data during emission of the saturation pulse. The facility is controlled to emit the first spoiler gradient pulse with the selected pulse parameter.
    Type: Grant
    Filed: August 28, 2019
    Date of Patent: June 15, 2021
    Assignee: Siemens Healthcare GmbH
    Inventors: Uvo Hoelscher, Michael Koehler, Daniel Niederloehner, Alto Stemmer
  • Patent number: 10989771
    Abstract: The disclosure relates to a method for triggered acquisition of a measured data set by a magnetic resonance system, to a corresponding computer program, to a corresponding data memory and to the corresponding magnetic resonance system. In the method, a cyclical signal is detected, which describes a cyclical change in a target object to be imaged. Cycles are automatically identified in this cyclical signal. Furthermore, at least one property of the cyclical signal is automatically determined. It is then automatically determined whether triggering of a single measurement for acquisition of some of the measured data set is permitted in an identified cycle of the cyclical signal. This determination is made as a function of the at least one determined property of the cyclical signal and a specified reference value of an acquisition parameter.
    Type: Grant
    Filed: July 18, 2019
    Date of Patent: April 27, 2021
    Assignee: Siemens Healthcare GmbH
    Inventor: Alto Stemmer
  • Patent number: 10888247
    Abstract: In a method for filtering magnetic resonance (MR) image data, complex MR image data is acquired from a region to be imaged, and a sliding window averaging is applied to the complex MR image data to generate filtered MR image data. For each window position of the sliding window averaging: a phase variation of the complex MR image data of individual image points of a sliding window is estimated with a model using a linear phase progression, and filtered complex MR image data is generated based on the estimated phase variation of the complex MR image data. The generation of the filtered complex MR image data uses an average formation of the complex MR image data of the individual image points of the sliding window.
    Type: Grant
    Filed: July 26, 2019
    Date of Patent: January 12, 2021
    Assignee: Siemens Healthcare GmbH
    Inventors: Marcel Dominik Nickel, Alto Stemmer
  • Patent number: 10718837
    Abstract: Some aspects of the present disclosure relate to ultrashort-echo-time (UTE) imaging. In one embodiment, a method includes acquiring UTE imaging data associated with an area of interest of a subject. The acquiring comprises applying an imaging pulse sequence with a three-dimensional (3D) spiral acquisition and a nonselective excitation pulse. The method also includes reconstructing at least one image of the area of interest from the acquired UTE imaging data.
    Type: Grant
    Filed: April 21, 2017
    Date of Patent: July 21, 2020
    Assignees: UNIVERSITY OF VIRGINIA PATENT FOUNDATION, SIEMENS HEALTHCARE GMBH
    Inventors: John P. Mugler, III, Samuel W. Fielden, G. Wilson Miller, IV, Craig H. Meyer, Talissa A. Altes, Alto Stemmer, Josef Pfeuffer, Berthold Kiefer
  • Patent number: 10705172
    Abstract: In a method and magnetic resonance (MR) apparatus for performing an adjustment of the MR system, an examination object under is divided into at least one excitation volume. First adjustment parameters for the at least one excitation volume of the object, and second adjustment parameters for the at least one excitation volume of the object, which differ from the first adjustment parameters are determined. First MR signals are acquired from the at least one excitation volume using the first adjustment parameters. Second MR signals are acquired from an excitation volume using the second adjustment parameters. A first MR image of the at least one excitation volume is reconstructed using the first MR signal. A second MR image of the at least one excitation volume is reconstructed using the second MR signal.
    Type: Grant
    Filed: February 24, 2017
    Date of Patent: July 7, 2020
    Assignee: Siemens Healthcare GmbH
    Inventors: Berthold Kiefer, Alto Stemmer
  • Publication number: 20200116807
    Abstract: Eddy current induced magnetic fields (MF) are compensated in a magnetic resonance imaging system. An MR-sequence (M) includes a number of gradients. A dataset includes values of an amplitude and a time constant of eddy current fields of a number of gradients on at least one gradient axis. A number of points in time within the time period of the MR-sequence are defined. A number of constant currents are calculated for a number of coils of the magnetic resonance imaging system based on the dataset. The number of constant currents is designed to compensate at least at the one defined point in time (PT1, PT2). The calculated number of constant currents are applied on the related coils prior or during the application of the MR-sequence or a section of the MR-sequence.
    Type: Application
    Filed: October 10, 2019
    Publication date: April 16, 2020
    Inventors: Uvo Hölscher, Michael Köhler, Daniel Niederlöhner, Alto Stemmer
  • Publication number: 20200072934
    Abstract: In a method for operating a magnetic resonance (MR) facility during recording of MR data by using a MR sequence including a saturation module for a spin type to be saturated, in which a high-frequency saturation pulse is emitted between first and second spoiler gradient pulses, and multiple further gradient pulses apart from the spoiler gradient pulses, eddy current data is determined. The eddy current data describes eddy currents existing during emission of the saturation pulse and resulting from the further gradient pulses. Further, a pulse parameter of the first spoiler gradient pulse is selected based on the eddy current data such that the eddy currents generated by the first spoiler gradient pulse compensate for at least part of the eddy currents described by the eddy current data during emission of the saturation pulse. The facility is controlled to emit the first spoiler gradient pulse with the selected pulse parameter.
    Type: Application
    Filed: August 28, 2019
    Publication date: March 5, 2020
    Applicant: Siemens Healthcare GmbH
    Inventors: Uvo Hoelscher, Michael Koehler, Daniel Niederloehner, Alto Stemmer
  • Publication number: 20200029854
    Abstract: In a method for filtering magnetic resonance (MR) image data, complex MR image data is acquired from a region to be imaged, and a sliding window averaging is applied to the complex MR image data to generate filtered MR image data. For each window position of the sliding window averaging: a phase variation of the complex MR image data of individual image points of a sliding window is estimated with a model using a linear phase progression, and filtered complex MR image data is generated based on the estimated phase variation of the complex MR image data. The generation of the filtered complex MR image data uses an average formation of the complex MR image data of the individual image points of the sliding window.
    Type: Application
    Filed: July 26, 2019
    Publication date: January 30, 2020
    Applicant: Siemens Healthcare GmbH
    Inventors: Marcel Dominik Nickel, Alto Stemmer
  • Publication number: 20200033426
    Abstract: The disclosure relates to a method for triggered acquisition of a measured data set by a magnetic resonance system, to a corresponding computer program, to a corresponding data memory and to the corresponding magnetic resonance system. In the method, a cyclical signal is detected, which describes a cyclical change in a target object to be imaged. Cycles are automatically identified in this cyclical signal. Furthermore, at least one property of the cyclical signal is automatically determined. It is then automatically determined whether triggering of a single measurement for acquisition of some of the measured data set is permitted in an identified cycle of the cyclical signal. This determination is made as a function of the at least one determined property of the cyclical signal and a specified reference value of an acquisition parameter.
    Type: Application
    Filed: July 18, 2019
    Publication date: January 30, 2020
    Inventor: Alto Stemmer
  • Patent number: 10379185
    Abstract: In a method and apparatus for acquiring magnetic resonance (MR) data from a subject, excitation pulses and at least two refocusing pulses are applied to the subject in an MR scanner, and the MR scanner is operated to activate gradients in a readout direction that cause at least two gradient echoes to be formed between the at least two successive refocusing pulses, with a temporal distance between the at least two gradient echoes that produces a predetermined phase shift between a signal acquired from a first nuclei in the subject and a signal acquired from a second nuclei in the subject at times of the respective gradient echoes, and that include readout gradients associated respectively with a first and a last gradient echo, among said at least two gradient echoes, the readout gradients being asymmetrical.
    Type: Grant
    Filed: July 30, 2015
    Date of Patent: August 13, 2019
    Assignee: Siemens Aktiengesellschaft
    Inventors: Alto Stemmer, Cong Zhao
  • Patent number: 10302729
    Abstract: In a magnetic resonance imaging system and operating method for generating magnetic resonance image data of an object under examination, in order to acquire magnetic resonance raw data, an operating sequence is determined that has an excitation wherein an RF excitation pulse is radiated, and a readout procedure for receiving RF signals. In addition, a diffusion contrast gradient pulse sequence is generated that includes an uneven number of 2n+1 diffusion contrast gradient pulses switched in chronological succession, with the sum of the zeroth gradient moments of the diffusion contrast gradient pulses having the value zero and the sum of the first gradient moments of the diffusion contrast gradient pulses having the value zero. An RF refocusing pulse is switched between two of the diffusion contrast gradient pulses.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: May 28, 2019
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 10145929
    Abstract: In a method and a controller for generating a parameter map for a target volume in an examination object, that represents a field deviation from the resonance frequency of a first spectral component of tissue of object in a magnetic resonance tomography scanner, a spatial region of the object, which includes at least the target volume, is excited. At least three echo signals are formed, wherein a first echo time difference between two the echo signals is chosen such that the phase evolutions of the signals of a second spectral component of the tissue differ, during the first echo time difference, from the first spectral component substantially by 2?, and an echo time of at least a further one of the echo signals is chosen such that it lies between the echo times of the two echo signals having the first echo time difference. Raw data are then acquired from the three echo signals, and the parameter map is then generated therefrom.
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: December 4, 2018
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 10126401
    Abstract: In a method and magnetic resonance (MR) tomography system for generating image data of a subject to be examined, situated in an MR scanner, during a magnetic resonance measurement the subject is repeatedly moved back and forth relative to a magnet/gradient system of the MR scanning between a starting position and an end position. During this movement, portions of a total raw image data set, which is required for the reconstruction of image data for slices of an image stack in the subject, are in each case acquired in different sweeps from the starting position to the end position and/or from the end position to the starting position.
    Type: Grant
    Filed: February 20, 2015
    Date of Patent: November 13, 2018
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 10067212
    Abstract: In method for determining a radial k-space trajectory, having multiple spokes, of an MR control sequence, a first whole number (N) is selected from a first subset of whole numbers. A first constant angular increment (d?) between respective spokes of the radial k-space trajectory that are spatially adjacent in k-space is determined as the quotient of ? and the first whole number N. Subsequently, a second constant angular increment (?k*d?) between spokes of the radial k-space trajectory that are measured sequentially in time is determined as the product from a second whole number (?k) and the first constant angular increment d?, wherein the second whole number ?k is determined from a second subset of whole numbers. The first subset of whole numbers and/or the second subset of whole numbers are/is the set of prime numbers.
    Type: Grant
    Filed: August 7, 2015
    Date of Patent: September 4, 2018
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 10031201
    Abstract: To enable improved reconstruction of magnetic resonance (MR) image data from MR scan data acquired from an examination object using dynamic shimming in an MR scanner that has a shim unit with at least one shim channel, an examination region of the object is divided into multiple sections, a B0 field of the examination region is scanned, and a B0 field map is thereby generated, a number of shim parameter sets are determined for the shim channel using the B0 field map, with a first shim parameter set of the number of shim parameter sets being determined for a first section of the multiple sections, and a second shim parameter set of the multiple shim parameter sets is determined for a second section of the multiple sections.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: July 24, 2018
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 10012713
    Abstract: A magnetic resonance control sequence with a pulse arrangement that acts selectively in at least two spatial directions in order to excite a limited rotationally symmetrical excitation profile within an examination subject has an RF excitation pulse formed as a sequence of multiple partial RF pulses, and gradient pulses in the two spatial directions that are coordinated with the partial RF pulses so that the RF energy introduction of different partial RF pulses in transmission k-space occurs on circular k-space transmission trajectories that are concentric to one another. The amplitude of the RF envelope of the partial RF pulses is constant during the duration of a traversal of each circular k-space trajectory. The control sequence can also be used in a calibration of a magnetic resonance system.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: July 3, 2018
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Patent number: 9841476
    Abstract: To enable improved adjustment of at least one shim channel for magnetic resonance imaging of an examination region of an examination object by operation of a magnetic resonance apparatus that has a shim arrangement with a first shim channel volume having at least one first shim channel and a second shim channel volume having at least one second shim channel, the examination region is divided into multiple of sections, multiple first shim parameter sets are determined for the at least one first shim channel, with one first shim parameter set among the multiple first shim parameter sets being ascertained for each of the multiple sections, a second shim parameter set is ascertained for the at least one second shim channel, taking into account the ascertained multiple first shim parameter sets, and magnetic resonance image data of the examination region are acquired, but before this acquisition, the at least one second shim channel is adjusted using the second shim parameter set and the at least one first shim ch
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: December 12, 2017
    Assignee: Siemens Aktiengesellschaft
    Inventor: Alto Stemmer
  • Publication number: 20170307705
    Abstract: Some aspects of the present disclosure relate to ultrashort-echo-time (UTE) imaging. In one embodiment, a method includes acquiring UTE imaging data associated with an area of interest of a subject. The acquiring comprises applying an imaging pulse sequence with a three-dimensional (3D) spiral acquisition and a nonselective excitation pulse. The method also includes reconstructing at least one image of the area of interest from the acquired UTE imaging data.
    Type: Application
    Filed: April 21, 2017
    Publication date: October 26, 2017
    Inventors: John P. Mugler, III, Samuel W. Fielden, G. Wilson Miller, IV, Craig H. Meyer, Talissa A. Altes, Alto Stemmer, Josef Pfeuffer, Berthold Kiefer
  • Publication number: 20170242089
    Abstract: In a method and magnetic resonance (MR) apparatus for performing an adjustment of the MR system, an examination object under is divided into at least one excitation volume. First adjustment parameters for the at least one excitation volume of the object, and second adjustment parameters for the at least one excitation volume of the object, which differ from the first adjustment parameters are determined. First MR signals are acquired from the at least one excitation volume using the first adjustment parameters. Second MR signals are acquired from an excitation volume using the second adjustment parameters. A first MR image of the at least one excitation volume is reconstructed using the first MR signal. A second MR image of the at least one excitation volume is reconstructed using the second MR signal.
    Type: Application
    Filed: February 24, 2017
    Publication date: August 24, 2017
    Applicant: Siemens Healthcare GmbH
    Inventors: Berthold Kiefer, Alto Stemmer