Patents by Inventor Joseph V. Hajnal

Joseph V. Hajnal 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: 20230096478
    Abstract: A method of operating a magnetic resonance scanner includes determining a radio frequency (RF) pulse to be transmitted to jointly homogenize a flip angle and a semisolid saturation that would result from magnetization of a sample to be scanned by the MR scanner using the determined RF pulse. The method also includes controlling an RF transmit coil of the MR scanner to transmit the determined pulse. Homogenizing both semisolid saturation and excitation properties of the RF pulse allows for improved magnetic transfer ratio imaging.
    Type: Application
    Filed: September 29, 2022
    Publication date: March 30, 2023
    Inventors: David Leitão, Raphael Tomi-Tricot, Joseph V. Hajnal, Shaihan Malik
  • Patent number: 6943547
    Abstract: In magnetic resonance imaging apparatus k-space data received from r.f. excitation pulses applied at successive phase-encode gradients and read-out while other gradients are applied is collected for individual coils of an array of r.f. receive coils. A processor 22 uses the lines of data received by each r.f. receive coil at each phase-encode gradient together with reference spatial sensitivity profiles of each coil in a phase-encode direction represented in terms of spatial harmonics of a fundamental frequency one cycle of which corresponds with a desired field of view, to generate a set of phase-encode lines. These lines are converted to image space in Fourier Transform processor 25 to produce an image for display on monitor 26.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: September 13, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Mark Bydder, Joseph V. Hajnal, David J. Larkman
  • Patent number: 6900631
    Abstract: In apparatus for magnetic resonance imaging equipped for parallel imaging, in the sense that an array of receive coils can be used to regenerate data at phase-encode gradients interposed between those at which measurements were taken, the full set of data is collected, which is then split into two sets with a greater separation of phase-encode gradients (FIGS. 13 and 14). These sets are then each regenerated (FIGS. 15 and 16), enabling spurious data to be excised from the original data set by comparison of the two representations.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: May 31, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Mark Bydder, David J. Larkman, Joseph V. Hajnal
  • Patent number: 6593741
    Abstract: Magnetic resonance imaging apparatus uses an array of at least two receive coils 4, 5 to perform parallel processing to enable phase-encode gradients to be omitted during data collection, and restored during processing using parallel processing to further reduce patient time in the apparatus, pre-acquired reference data is used (modules 10, 11) to unfold the aliased target data in modules 8, 9. In accordance with the invention, the unfolding is performed against a series of representations of the reference data, varied for translational rotational and coil loading errors, and the unfolded image is chosen as that having the minimum entropy.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: July 15, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Mark Bydder, Joseph V. Hajnal, David J. Larkman
  • Publication number: 20030076099
    Abstract: Better signal-to-noise ratio is obtained when combining the images from an array coil used in magnetic resonance imaging apparatus by using the relative sensitivity of each coil obtained by division of the images from each coil on a pixel-by-pixel basis.
    Type: Application
    Filed: April 19, 2002
    Publication date: April 24, 2003
    Inventors: Joseph V. Hajnal, Mark Bydder, David J. Larkman
  • Publication number: 20030030437
    Abstract: In magnetic resonance imaging apparatus k-space data received from r.f. excitation pulses applied at successive phase-encode gradients and read-out while other gradients are applied is collected for individual coils of an array of r.f. receive coils. A processor 22 uses the lines of data received by each r.f. receive coil at each phase-encode gradient together with reference spatial sensitivity profiles of each coil in a phase-encode direction represented in terms of spatial harmonics of a fundamental frequency one cycle of which corresponds with a desired field of view, to generate a set of phase-encode lines. These lines are converted to image space in Fourier Transform processor 25 to produce an image for display on monitor 26.
    Type: Application
    Filed: April 19, 2002
    Publication date: February 13, 2003
    Inventors: Mark Bydder, Joseph V. Hajnal, David J. Larkman
  • Publication number: 20030025499
    Abstract: Magnetic resonance imaging apparatus uses an array of at least two receive coils 4, 5 to perform parallel processing to enable phase-encode gradients to be omitted during data collection, and restored during processing using parallel processing to further reduce patient time in the apparatus, pre-acquired reference data is used (modules 10, 11) to unfold the aliased target data in modules 8, 9. In accordance with the invention, the unfolding is performed against a series of representations of the reference data, varied for translational rotational and coil loading errors, and the unfolded image is chosen as that having the minimum entropy.
    Type: Application
    Filed: April 19, 2002
    Publication date: February 6, 2003
    Inventors: Mark Bydder, Joseph V. Hajnal, David J. Larkman
  • Publication number: 20030025500
    Abstract: In apparatus for magnetic resonance imaging equipped for parallel imaging, in the sense that an array of receive coils can be used to regenerate data at phase-encode gradients interposed between those at which measurements were taken, the full set of data is collected, which is then split into two sets with a greater separation of phase-encode gradients (FIGS. 13 and 14). These sets are then each regenerated (FIGS. 15 and 16), enabling spurious data to be excised from the original data set by comparison of the two representations.
    Type: Application
    Filed: April 19, 2002
    Publication date: February 6, 2003
    Inventors: Mark Bydder, David J. Larkman, Joseph V. Hajnal
  • Patent number: 5528144
    Abstract: An examination region (34) is divided into a multiplicity of slices, e.g. slices 1-20. The slices are divided up into groups or slabs, e.g., slabs I-V. A series of magnetization inversion pulses (70.sub.I- 70.sub.V) and slab select gradient pulses (74.sub.I -74.sub.V) are applied at regular intervals. At a duration after each slab inversion at which the magnetization of a material such as CSF is at a minimum or null (80) marks a center of a data acquisition period (84). A plurality of imaging sequences (82) are conducted in each data acquisition period. Each of the imaging sequences collects one or more data lines from each of the slices within the corresponding slab. This process is repeated cyclically until all of the data lines of each slice of each slab have been collected. The data lines are reconstructed (102) into an image representation which is stored in an image memory (104) for selective display on a video monitor (108).
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: June 18, 1996
    Assignee: Picker International, Inc.
    Inventors: Rao P. Gullapalli, Joseph V. Hajnal, Haiying Liu, Larry Kasuboski