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).

  • Publication number: 20110133735
    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: Application
    Filed: May 22, 2009
    Publication date: June 9, 2011
    Inventors: Suguru Yokosawa, Yo Taniguchi, Yoshitaka Bito, Hiroyuki Itagaki
  • Publication number: 20110121834
    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: Application
    Filed: July 22, 2009
    Publication date: May 26, 2011
    Applicant: HITACHI MEDICAL CORPORATION
    Inventors: Yoshihisa Soutome, Hideta Habara, Yoshitaka Bito
  • Publication number: 20110112393
    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: Application
    Filed: July 22, 2009
    Publication date: May 12, 2011
    Inventors: Yo Taniguchi, Yoshitaka Bito, Shoichi Miyawaki, Hiroyuki Takeuchi, Suguru Yokosawa
  • Patent number: 7884609
    Abstract: To provide an RF coil of an MRI apparatus and improve the irradiation efficiency and the reception sensitivity of a circular polarized magnetic field with a simple structure. An RF coil has a set of input/output terminals and two loops. The two loops are disposed and capacitors in the loops are adjusted so that the linearly polarized magnetic fields generated and detected by the loops are perpendicular to each other, and the combined magnetic field of the linearly polarized magnetic fields is a circular polarized magnetic field.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: February 8, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihisa Soutome, Hideta Habara, Yoshitaka Bito
  • Patent number: 7868614
    Abstract: The invention provides a magnetic resonance system and method of measuring continuous regions at high speed without decreasing SN. As a receive system, multiple RF coil sets a, b comprising multiple RF coils a1, a2, b1, b2 are disposed in positions where there is no spatial interference with at least one of the RF coils of an adjacent coil set, the RF coils constituting each coil set are changed over one by one, sets of RF coils which do not interfere mutually are activated, and signals are simultaneously acquired from a number of regions equivalent to the number n of coil sets. Hence, if the number of coil sets is set to n, the measurement time can be shortened to 1/n. Alternatively, the SN can be improved by ?n times.
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: January 11, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Bito, Hisaaki Ochi
  • Publication number: 20100272337
    Abstract: While removing signals unnecessary for measuring signals from a metabolite, data required for eddy current correction are obtained in a short period of time. Signals from an unnecessary substance which is not an object of the measurement are removed, and phase data for correcting spectral distortion caused by an eddy current are obtained by a single measurement. Two kinds of frequency-selective pulses of which intensities are adjusted so that the signals from the unnecessary substance should have the same absolute values of intensities and opposite polarities are applied with changing intensities for every phase encoding for at least one axis, and the obtained signals are arranged in a k-space. By removing aliasing of image data obtained from the k-space data, signals from an unnecessary substance are removed, and phase data for eddy current correction are calculated by using a part of the k-space data.
    Type: Application
    Filed: July 7, 2008
    Publication date: October 28, 2010
    Inventors: Toru Shirai, Yoshitaka Bito, Yukari Yamamoto, Satoshi Hirata
  • Publication number: 20100272336
    Abstract: In the continuous moving table imaging, an image is reconstructed with suppressed artifacts even in imaging under inhomogeneity of static magnetic field. In a magnetic resonance imaging apparatus, signals are measured with moving a table to obtain multiple data sets, and inverse Fourier transform of each data set is carried out in the read-out direction to obtain hybrid data. One-dimensional data are extracted from each hybrid data at a border with respect to the adjacent hybrid data, and correction values for corrections of discontinuity of signal intensity and phase at a border of hybrid data are obtained by using the one-dimensional data. Data obtained by inverse Fourier transform of each hybrid data are corrected by using the correction values, and an image showing continuity for signal intensity and phase is eventually obtained.
    Type: Application
    Filed: April 28, 2008
    Publication date: October 28, 2010
    Inventors: Yo Taniguchi, Shinji Kurokawa, Suguru Yokosawa, Yoshitaka Bito
  • Publication number: 20100253347
    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: Application
    Filed: February 9, 2010
    Publication date: October 7, 2010
    Applicant: HITACHI MEDICAL CORPORATION
    Inventors: Hideta HABARA, Yoshitaka BITO, Hisaaki OCHI, Yoshihisa SOUTOME, Masayoshi DOHATA, Tetsuhiko TAKAHASHI, Hiroyuki TAKEUCHI
  • Patent number: 7733092
    Abstract: Provided is an RF coil which can highly efficiently and uniformly irradiate a RF magnetic field having two or more magnetic resonance frequencies close to each other, and receive magnetic resonance signals of two or more magnetic resonance frequencies close to each other with high sensitivity and uniform sensitivity profile in an MRI apparatus. Two or more frequencies to which the coil is tuned are adjusted so as to be between resonance frequencies of series resonant circuits constituting the RF coil.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: June 8, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yosuke Otake, Yoshihisa Soutome, Koji Hirata, Yoshitaka Bito
  • Publication number: 20100131506
    Abstract: An association rule is extracted by processing a database partitioned into record units in which the same attribute is missing, from a database including missing values. The association rule is extracted from the database including the missing by means for partitioning a database so that a database including a missing analysis object becomes record blocks in which the same attribute is missing, and means for estimating an upper threshold of a support value in the entire database from local support counts in partitioned databases and thereby limiting records for which the support count is counted.
    Type: Application
    Filed: March 7, 2006
    Publication date: May 27, 2010
    Inventors: Takahiko Shintani, Yoshitaka Bito
  • Patent number: 7723987
    Abstract: A magnetic resonance measurement technique is provided which shortens the measurement time while suppressing artifacts caused by body movement of a measuring object and enables high-speed imaging. An excitation pulse which excites a plurality of slice planes and an excitation pulse which excites slice planes perpendicular to the slice planes are applied and a plurality of substantially parallel linear crossing areas are simultaneously measured. Spatial information of a linear direction of the crossing areas is acquired by modulating a magnetic resonance signal from the crossing areas by a gradient magnetic field. A spatial information of a direction perpendicular to the linear direction is acquired by changing the position of the plane and an image is reconstructed.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: May 25, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Bito, Yo Taniguchi, Toru Shirai, Shinji Kurokawa
  • Publication number: 20100097062
    Abstract: A method for obtaining the most appropriate amplitude of signal suppression pulse, which suppresses unnecessary signals from the substance not subjected to measurement, highly accurately, swiftly and stably, and an MRI apparatus that enables the optimization are provided. A pulse amplitude adjusting means equipped in the MRI apparatus acquires signals while changing the amplitude of signal suppression pulse and calculates signal absolute values and phase values, and computes reference signals, which are polarized signal absolute values, based on the changes in signal phase values. This reference signals are subjected to polynomial fitting. A value which makes this fitting curve is 0 or closes to 0 is set as the optimal pulse amplitude.
    Type: Application
    Filed: June 29, 2007
    Publication date: April 22, 2010
    Inventors: Toru Shirai, Yoshitaka Bito, Yo Taniguchi, Satoshi Hirata
  • Publication number: 20100013481
    Abstract: An object of the invention is to obtain a magnetic resonance spectroscopic image to which the MAC summation is applied with high accuracy and in short time, even though a phase characteristic distribution of the MAC has a spatial non-uniformity, in the MRSI measurement using a magnetic resonance imaging apparatus provided with a MAC. Using a non-water-suppressed image signal with high SNR, obtained in the non-water-suppressed measurement (a reference measurement) without water suppression, a correction value for correcting the phase distortion for the MAC summation is calculated on each pixel in each coil. After correcting a phase on each pixel in each coil of a main-scan image signal measured under suppressing water (water-suppressed image signal) using the corrective value, signal adding operation (summation) is performed. Then, a phase correction in a spectrum-axis is to be performed on the summed spectrum signal.
    Type: Application
    Filed: December 17, 2007
    Publication date: January 21, 2010
    Inventors: Satoshi Hirata, Yoshitaka Bito, Kiyoharu Tanaka
  • Patent number: 7639012
    Abstract: There is provided an RF coil capable of resonating or tuning two frequencies, having uniform spatial sensitivity and having a small spatially occupied volume, especially an RF coil suitable for a high magnetic field MRI apparatus. A coil apparatus is made up of a plurality of linear conductors 200, 201 arranged around a central axis and two ring conductors 202, 203 connected to the respective ends of the plurality of linear conductors 200, 201 and capacitors are inserted in the linear conductors 200, 201 and ring conductors 202, 203. The plurality of linear conductors are made up of conductors 200 located near the central axis and conductors 201 located far from the central axis and the ring conductors 202, 203 have star-like polygonal shape so that the linear conductors are arranged alternately.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: December 29, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Hideta Habara, Yoshitaka Bito, Yoshihisa Soutome, Hisaaki Ochi
  • Publication number: 20090251145
    Abstract: An RF coil for MR Imaging that can change a resonance frequency easily and instantaneously in response to a nuclide to be imaged without exchange and adjustment and that also causes only small lowering of sensitivity. The RF coil has a sub coil for changing a resonance frequency of the transmitting/receiving RF coil for transmitting and receiving an MR signal between itself and a nuclide that is an object to be imaged. The sub coil is equipped with a switch, and at the time of switching-on, shifts the resonance frequency of the RF coil by changing an inductance value of the RF coil in a noncontact manner using inductance coupling.
    Type: Application
    Filed: April 3, 2009
    Publication date: October 8, 2009
    Inventors: Yukio KANEKO, Hideta HABARA, Yoshihisa SOUTOME, Yosuke OTAKE, Yoshitaka BITO
  • Patent number: 7589530
    Abstract: An RF coil which is resonant and tuned with two different frequencies, has uniform space sensitivity and occupies less space is provided. The coil is, particularly suited to the high magnetic field MRI apparatus. The coil device is equipped with the multiple number of first coils 200 having the first conducting sections 201 and 202 and the second conducting sections 203 and 204, and the second coils 205 and 206 electrically connected with the end of the multiple number of first coils. In the first conducting sections, two conducting parts 201 and 202 are electrically connected via the first condenser 207, while in the second conducting sections, two conducting parts 203 and 204 are electrically connected via the second condenser 208. And the feeding circuit and/or receiving circuit are connected in parallel with the first condenser at one or two positions.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: September 15, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Hideta Habara, Yoshitaka Bito, Yoshihisa Soutome, Hisaaki Ochi
  • Patent number: 7552062
    Abstract: There is provided a process analysis method capable of clustering of executed processes and extraction of similar processes. A process analysis method of the present invention converts the similarity between processes into a numeric value as a metric by including a process matrix transform 12 and a metric calculation 14 for process records 11 made up of a series of records of rendered service of at least three elements of the time of service, the type of service, and the quantity of service. This enables the calculation of the similarity between processes as a metric from information of only a series of records of rendered services. Accordingly, it becomes possible to cluster the executed processes and to extract similar processes based on the metric herein calculated.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: June 23, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Bito, Shigeo Sumino, Hajime Sasaki, Hitoshi Matsuo, Yoshiyuki Nakayama
  • Publication number: 20090154304
    Abstract: An information memory device using an electromagnetic-wave resonance phenomenon is provided to achieve both high density and long-period storage of stored data. Memory cells are three-dimensionally arranged in the inside of a solid-like medium which is not contacted with a surface of the medium, and the memory cell has resonance characteristics to electromagnetic waves depending on the space coordinates of the memory cell. For the medium, a material is selected so that an electromagnetic wave having the resonance frequency of the memory cell. By observing absorption spectra of the irradiated electromagnetic wave or emission spectra after the absorption, three-dimensional space coordinates of the memory cell are calculated.
    Type: Application
    Filed: December 17, 2008
    Publication date: June 18, 2009
    Inventors: Takao Watanabe, Toshimichi Shintani, Takeshi Maeda, Akemi Hirotsune, Yoshitaka Bito
  • Publication number: 20090128155
    Abstract: An RF coil having at least three different resonance frequencies, wherein one of the resonance frequencies is adjusted to be a frequency fA of a magnetic resonance signal generated by a test subject, and the coil is adjusted so that ratio of difference between the frequency fA and a first frequency fB lower than fA and nearest to fA among the resonance frequencies (fA?fB), and difference between the frequency fA and a second resonance frequency fC higher than fA and nearest to the frequency fA among the resonance frequencies(fC?fA), should be from 0.5 to 2.0. There is provided a technique for receiving magnetic resonance signals always with high detection efficiency by an RF coil of an MRI apparatus even if significant loss is caused in the RF coil, or test subject is changed.
    Type: Application
    Filed: November 19, 2008
    Publication date: May 21, 2009
    Inventors: Yosuke Otake, Yoshihisa Soutome, Koji Hirata, Yoshitaka Bito
  • Publication number: 20090108842
    Abstract: An MRI apparatus comprises a waveform controlling means for calculating a radio frequency pulse and applying the pulse to an irradiating means, and the waveform controlling means reads out a radio frequency pulse waveform vector from a first memory means which memorizes multiple radio frequency pulse waveform vectors, calculates a simulated irradiation pattern, and calculates a radio frequency pulse waveform which gives the minimum value of weighted sum of squares of differences of absolute values and squares of differences of phases for an ideal irradiation pattern and the simulated irradiation pattern. An RF pulse waveform showing superior ideal irradiation pattern reproducibility and providing reduced power of the RF waveform is formed, and safety of MRI subject is improved by performing imaging using such an RF pulse.
    Type: Application
    Filed: October 29, 2008
    Publication date: April 30, 2009
    Inventors: Hideta HABARA, Yoshitaka Bito