Patents by Inventor Yoshitaka Bito

Yoshitaka Bito 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: 8803526
    Abstract: The present invention provides a technique for maintaining a function for effectively blocking common mode noise with a simple configuration, even in the case where unbalance occurs in characteristic impedance of a coaxial cable in an MRI apparatus, and improving the performance of an RF coil. In a circuit where a balun is established by parallel connection with the coaxial cable, multiple serial resonance circuits having different resonance frequencies are connected in parallel. A value of each constitutional element of each of the serial resonance circuits is adjusted in such a manner that the frequency for blocking the common mode noise of the entire balun falls into a range between the resonance frequencies of these serial resonance circuits.
    Type: Grant
    Filed: January 28, 2010
    Date of Patent: August 12, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Yosuke Otake, Yoshihisa Soutome, Yukio Kaneko, Yoshitaka Bito, Hisaaki Ochi, Koji Hirata
  • Publication number: 20140219533
    Abstract: There is provided a technique for obtaining a magnetic susceptibility-weighted image in which contrast difference of a tissue of interest and a surrounding tissue can be emphasized regardless of the positional relationship of the B0 direction and the imaging slice. A phase image is converted into a susceptibility map not depending on the B0 direction, and then a weighting image used for weighting is generated by using the susceptibility map. The weighting image to be generated is for emphasizing contrast of a tissue of interest and a surrounding tissue depending on the purpose. Then, by multiplication of the weighting image and an absolute image, a magnetic susceptibility-weighted image in which the magnetic susceptibility difference is emphasized depending on the purpose is obtained.
    Type: Application
    Filed: October 3, 2012
    Publication date: August 7, 2014
    Inventors: Ryota Sato, Toru Shirai, Yo Taniguchi, Yoshihisa Soutome, Yoshitaka Bito
  • Patent number: 8787639
    Abstract: Water/fat separation imaging is performed by an MRI device, even if the measurement is not performed with such echo times that the phases of water and fat signals become in-phase or out-of-phase. A determination is made as to which of two obtained separation images is a water image or a fat image. Two water/fat ratio maps are calculated from two original images obtained with such two echo times that phase differences of water and fat signals do not become positive and negative values, and do not becomes integral multiples of ?. Two phase maps are calculated from the two water/fat ratio maps and are combined to calculate two minimum phase difference maps showing minimum spatial phase difference. From dispersion in differential maps obtained by spatially differentiating the minimum phase difference maps, a correct minimum phase difference map is determined, and is used to perform phase correction of the original image.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: July 22, 2014
    Assignee: Hitachi Medical Corporation
    Inventors: Toru Shirai, Yoshitaka Bito
  • Publication number: 20140191756
    Abstract: A technique in a medical imaging apparatus being capable of setting any plane in three-dimensional space as an imaging slice is provided, allowing an automatically-set imaging slice to be configured to suit user's preferences, and determine a position of the imaging slice being configured, with respect to an imaging target subject automatically with a high degree of accuracy. Reference information for specifying the imaging slice, set by the user for each imaging site, is associated with the anatomical feature of the imaging site, so as to generate an imaging slice parameter. Upon actual imaging, the imaging slice parameter and the anatomical feature of the imaging target subject obtained by scout imaging are used to determine the imaging slice position of the imaging target subject.
    Type: Application
    Filed: July 27, 2012
    Publication date: July 10, 2014
    Inventors: Suguru Yokosawa, Yo Taniguchi, Yoshitaka Bito, Yoshihisa Soutome
  • Patent number: 8742759
    Abstract: There is provided a high-frequency coil of an MRI device, which can easily and highly reproducibly reduce electromagnetic coupling between adjacent surface coils among a plurality of surface coils disposed with intervals. An electromagnetic decoupling coil that can generate a magnetic flux for canceling a magnetic flux generated by one of the adjacent surface coils and interlinking with the other surface coil is disposed between the adjacent surface coils. The electromagnetic decoupling coil is provided with a capacitor, and is tuned by means of the capacitor so that the electromagnetic coupling should be minimized in such a range that the resonance frequency thereof should be lower than the resonance frequency of the surface coils.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: June 3, 2014
    Assignee: Hitachi Medical Corporation
    Inventors: Yoshihisa Soutome, Hideta Habara, Yoshitaka Bito
  • Publication number: 20140103931
    Abstract: The present invention is directed to an elliptical birdcage coil which reduces time and effort upon manufacturing and production cost, with less variations in performance. There is provided a high frequency coil unit made up of the elliptical birdcage coil having plural capacitors arranged at least on either of the ring conductors and the rung conductors, the capacitance of the plural capacitors being uniform with respect to each conductor type on which the capacitors are placed. In this elliptical birdcage coil, a value of inductance and arrangement of the ring conductors and the rung conductors are determined in such a manner that the capacitance of the capacitors becomes identical with respect to each conductor type on which the capacitors are arranged.
    Type: Application
    Filed: April 6, 2012
    Publication date: April 17, 2014
    Applicant: HITACHI, LTD.
    Inventors: Yoshihisa Soutome, Yoshitaka Bito, Hideta Habara
  • Patent number: 8693760
    Abstract: There is provided a technique for, in a medical imaging apparatus enabling imaging of an arbitrary plane in a three-dimensional space, enabling automatic calculation of a slice position and automatic calculation of an extracting slice in MPR, without prolonging examination time. Two-dimensional scout scan similar to that used for manual setting of a slice position is performed, and the obtained scout images are processed to calculate a recommended slice position. Algorithms for the processing and various image processing procedures used for the processing are stored beforehand for every type of imaging region and every type of examination.
    Type: Grant
    Filed: June 22, 2010
    Date of Patent: April 8, 2014
    Assignee: Hitachi Medical Corporation
    Inventors: Suguru Yokosawa, Yo Taniguchi, Yoshitaka Bito
  • Patent number: 8648597
    Abstract: An RF coil is provided with a hollow-shaped outer conductive element and strip-shaped conductive elements disposed along the outer conductive element in the axial direction. The strip-shaped conductive elements are disposed with uneven intervals to secure an internal space at a position where the strip-shaped conductive elements are not disposed. In order to obtain uniform sensitivity at the center section of the RF coil, the strip-shaped conductive elements and the outer conductive element are electrically connected via capacitors of which capacitances are adjusted so that a magnetic field component perpendicular to the center axis should be generated at a desired resonance frequency, and the strip-shaped conductive elements are axisymmetrically disposed with respect to the center axis of the outer conductive element. As a result, a comfortable examination space in a tunnel type MRI apparatus is achieved without increasing the manufacturing cost of the MRI apparatus.
    Type: Grant
    Filed: February 9, 2010
    Date of Patent: February 11, 2014
    Assignee: Hitachi Medical Corporation
    Inventors: Hideta Habara, Yoshitaka Bito, Hisaaki Ochi, Yoshihisa Soutome, Masayoshi Dohata, Tetsuhiko Takahashi, Hiroyuki Takeuchi
  • Patent number: 8614574
    Abstract: A magnetic resonance imaging apparatus is provided, which is capable of reducing SAR while maintaining S/N ratio and image contrast in a GrE-type pulse sequence, regardless of whether a synchronous imaging is performed or not. The present invention controls a flip angle as to each measurement set 409 that is obtained by division according to the size of phase encoding and a body motion cycle of a subject in the GrE-type pulse sequence. In a set 501 which measures echoes with phase encoding having a minimum absolute value, the flip angle is maximized as to the RF pulse having a minimum phase encoding amount and at least one RF pulse irradiated immediately before. As for the other RF pulses, the flip angle varies within a range less than the maximum, irrespective of the non-imaging mode, the imaging mode, or the size of phase encoding.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: December 24, 2013
    Assignee: Hitachi Medical Corporation
    Inventors: Suguru Yokosawa, Yo Taniguchi, Yoshitaka Bito, Hiroyuki Itagaki
  • Publication number: 20130314090
    Abstract: In order to improve image quality, a technique for obtaining information for eliminating distortions of the k-space in the readout direction and the phase encoding direction caused by the waveform distortion of the gradient magnetic field pulse is provided. A pulse sequence for the main scan is used to repeatedly measure echoes with changing the time integral value of the dephasing pulse for the readout gradient magnetic field. In the above measurement, the phase encoding pulse is not made zero, but two-dimensional data are measured in the same manner as that of the main scan. By using the measured two-dimensional data, correction information for eliminating distortions of the k-space in the readout direction and the phase encoding direction caused by the waveform distortion of the gradient magnetic field pulse is calculated in each of the readout direction and the phase encoding direction.
    Type: Application
    Filed: January 19, 2012
    Publication date: November 28, 2013
    Applicant: HITACHI, LTD.
    Inventors: Yo Taniguchi, Suguru Yokosawa, Yoshitaka Bito
  • Publication number: 20130314091
    Abstract: To provide a technique for sufficiently eliminating magnetic coupling between RF coils and improving image quality when a multi-element multi-tuned RF coil is used as a receive RF coil for an MRI device. In the invention, each of RF coils which constitute a multi-element multi-tuned RF coil which is used as a receive RF coil for an MRI device is provided with an inter-coil magnetic coupling prevention circuit which resonates at each frequency to which each RF coil is tuned and provides a high impedance. The inter-coil magnetic coupling prevention circuit adjusts an inductor and a capacitor so that both of a circuit on the side of a pre-amplifier viewed from both ends of a signal reception circuit and a circuit on the side of the signal reception circuit viewed from both ends of a serial resonance circuit connected to the pre-amplifier resonate at a plurality of frequencies to which the respective RF coils are tuned.
    Type: Application
    Filed: February 1, 2012
    Publication date: November 28, 2013
    Applicant: HITACHI, LTD.
    Inventors: Yosuke Otake, Yoshihisa Soutome, Ryota Sato, Yoshitaka Bito, Koji Hirata
  • Patent number: 8587310
    Abstract: In the diffusion-weighted imaging, amounts of distortion and amounts of phase offset of k-space data due to a temporally changing magnetic field error induced by eddy currents and vibrations associated with application of a diffusion-weighted gradient magnetic field pulse are corrected with good precision to improve image quality. Characteristic data for correcting distortion of k-space data are calculated for every position in the slice direction as peak shifts of projections observed between the cases of applying and not applying an MPG pulse. As the characteristic data, amounts of distortion in the read-out direction and the phase encoding direction and phase offset amounts in a slice plane are calculated.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: November 19, 2013
    Assignee: Hitachi Medical Corporation
    Inventors: Yo Taniguchi, Yoshitaka Bito, Shoichi Miyawaki, Hiroyuki Takeuchi, Suguru Yokosawa
  • Patent number: 8547101
    Abstract: In MRS measurement using magnetic resonance highly precise results are efficiently obtained with coincidence of axes with axes in positioning image. In measurement according to the PRESS method for a plurality of regions each localized (specified) with a set of perpendicularly intersecting three slices, wherein one or two slices are common to the sets of three slices localizing the regions, and slices not common do not intersect, a slice not common to those of a region to be selectively excited is excited with a radio frequency magnetic field of which phase is different by 180 degrees from that of a radio frequency magnetic field used for exciting the region to be selectively excited a number of times equal to the number of common slices, and during the measurement of the region to be selectively excited, a group of regions other than the region to be selectively excited are thermally equilibrated.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: October 1, 2013
    Assignee: Hitachi Medical Corporation
    Inventors: Satoshi Hirata, Yoshitaka Bito
  • Publication number: 20130221968
    Abstract: There is provided a technique for suppressing increase of SAR without sacrificing sensitivity in RF coils used in MRI apparatuses. The present invention provides an antenna device comprising a sheet-shaped conductor and a ribbon-shaped conductor disposed on the subject side with respect to the sheet-shaped conductor with a predetermined distance from the sheet-shaped conductor. The ribbon-shaped conductor has a meandering shape, and is adjusted so as to resonate at transmission and reception frequencies, and it is constituted so that distance to the sheet-shaped conductor becomes smaller at both end part thereof along the static magnetic field direction compared with the distance to the sheet-shaped conductor at the center thereof. Moreover, the ribbon-shaped conductor is constituted so as to have a smaller width, as the distance to the sheet-shaped conductor becomes smaller.
    Type: Application
    Filed: October 6, 2011
    Publication date: August 29, 2013
    Inventors: Hideta Habara, Yoshitaka Bito, Hisaaki Ochi, Yoshihisa Soutome, Masayoshi Dohata, Tetsuhiko Takahashi, Hiroyuki Takeuchi
  • Publication number: 20130214785
    Abstract: Images of two or more kinds of substances showing different chemical shifts, such as water image and metabolite image, are obtained without extending measurement time. For example, images of two or more kinds of desired substances showing different chemical shifts, such as water image and metabolite image, are obtained by one time of execution of an imaging sequence. In this execution, a pre-pulse is applied so that signals of the substances to be separated shift on the image, and magnetic resonance signals are received with receiver RF coils in a number not smaller than the number of types of the substances to be separated. An image reconstructed from the magnetic resonance signals is separated into images of the individual substances using sensitivity maps of the receiver RF coils. Then, correction is performed for returning the shifted image to the original position.
    Type: Application
    Filed: October 26, 2011
    Publication date: August 22, 2013
    Inventors: Toru Shirai, Yoshitaka Bito, Satoshi Hirata, Yoshihisa Soutome, Yo Taniguchi
  • Publication number: 20130119991
    Abstract: A technique is provided to reserve large examination space in the tunnel type MRI apparatus, without increasing production cost nor reducing significantly irradiation efficiency and homogeneity in an irradiation distribution within an imaging region. The present invention provides an RF coil unit in which four partial cylindrical coils are placed with a gap therebetween in the circumferential direction inside a cylindrical RF shield, in such a manner that two pairs of the partial cylindrical coils are opposed to each other, and magnetic fields produced by the individual partial cylindrical coils are combined, thereby producing a circularly polarized wave field or an elliptically polarized wave field.
    Type: Application
    Filed: July 25, 2011
    Publication date: May 16, 2013
    Inventors: Yoshihisa Soutome, Yoshitaka Bito, Hiroyuki Takeuchi, Tetsuhiko Takahashi, Hisaaki Ochi, Hideta Habara
  • Publication number: 20130082708
    Abstract: B1 distribution is calculated in a short time with a high degree of precision, and a high quality image is obtained. In the RF shimming for irradiating electromagnetic waves using an RF coil having multiple channels, the absolute values of subtraction images between multiple reconstructed images are used to calculate a transmitting sensitivity distribution which is necessary for calculating inter-channel phase difference and amplitude ratio of RF pulses provided to the respective channels. Those multiple reconstructed images are obtained by executing the imaging sequence after applying a prepulse at different flip angles respectively. Assuming an image obtained with a minimum flip angle as a reference image, for instance, the subtraction images are created between the reference image and the other respective images. It is also possible that multiple subtraction images being obtained are divided by one another, and the transmitting sensitivity distribution is created on the basis of the division result.
    Type: Application
    Filed: June 6, 2011
    Publication date: April 4, 2013
    Applicant: Hitachi Medical Corporation
    Inventors: Suguru Yokosawa, Yo Taniguchi, Yoshitaka Bito, Yukio Kaneko
  • Publication number: 20130069652
    Abstract: There is a provided a technology of receiving a magnetic resonance signal highly sensitively and with a uniform sensitivity distribution in an RF coil of an MRI device which is an RF coil including a switch circuit of switching a circuit configuration. The RF coil of the MRI device of the present invention includes a switch circuit of switching a circuit configuration. Also, the switch circuit switches the circuit configuration by being driven by a control signal received by wireless. For that purpose, the switch circuit includes an antenna of receiving the control signal and a conversion circuit of converting an alternating current voltage received into a direct current voltage.
    Type: Application
    Filed: January 25, 2011
    Publication date: March 21, 2013
    Inventors: Yosuke Otake, Yoshihisa Soutome, Yukio Kaneko, Yoshitaka Bito, Hisaaki Ochi, Koji Hirata
  • Publication number: 20130057285
    Abstract: An object of the present invention is to provide a measuring technique which allows in the MRS measurement to suppress with a high degree of precision, incorporation of a signal of unwanted compounds which hinders measurement of a measurement object signal, independent of an imaging object region and the measurement object signal, thereby obtaining a stable and favorable signal spectrum. In the MRS measuring sequence, a spectrum selective inversion RF pulse, having a narrow band characteristic for selectively inverting only a signal peak of a compounds to be suppressed, and phase dispersion-refocusing GC pulses are applied at least one of before and after a region selective RF pulse. This MRS measuring sequence is repeated while changing the echo time TE at predetermined intervals, and nuclear magnetic resonance signals being obtained by the repetition are integrated. The amount of the spectrum selective inversion RF pulse to be applied may be changed according to the echo time TE.
    Type: Application
    Filed: May 2, 2011
    Publication date: March 7, 2013
    Inventors: Satoshi Hirata, Yoshitaka Bito
  • Publication number: 20130049753
    Abstract: The present invention provides an image processing technique which enables various contrast control, by quantitatively handling a degree of phase enhancement in a contrast control as a post-processing of the image reconstruction. A complex operation is performed on each pixel value of a complex image obtained by an MRI, thereby generating an image with desired contrast. Intensity is controlled by increasing or decreasing the argument of the pixel value of each pixel by a constant amount, and the degree of phase enhancement is controlled by multiplying the phase (argument) of each pixel by a constant.
    Type: Application
    Filed: April 20, 2011
    Publication date: February 28, 2013
    Inventors: Yo Taniguchi, Yoshitaka Bito, Tetsuhiko Takahashi, Takenori Murase