Abstract: Appropriate processing is executed in a method for excluding body motion data and image reconstruction according to a type and a characteristic of a body motion, so as to reduce an influence of the body motion, and prevent deterioration of image quality caused by exclusion of data generated during the body motion. An MRI apparatus includes a processing determination unit that collects k-space data and acquires body motion information from a sensor capable of detecting not only a respiratory motion but also general body motions, analyzes the body motion information obtained by the sensor, and branches and executes processing for subsequent data collection and image reconstruction according to the analysis result.

Abstract: The receiving coil device includes one or a plurality of receiving coils configured to cover a head of a subject, a base portion on which the head of the subject is to be placed, a holder portion supported by the base portion, one of the receiving coils being fixed to the holder portion, a mechanism portion configured to bring the receiving coil fixed to the holder portion into close contact with a part of the head, and further, a detection unit configured to detect a physical quantity related to a displacement of the holder portion on the holder portion or the base portion. The physical quantity detected by the detection unit is sent to an MRI apparatus including the receiving coil device.

Abstract: Appropriate processing is executed in a method for excluding body motion data and image reconstruction according to a type and a characteristic of a body motion, so as to reduce an influence of the body motion, and prevent deterioration of image quality caused by exclusion of data generated during the body motion. An MRI apparatus includes a processing determination unit that collects k-space data and acquires body motion information from a sensor capable of detecting not only a respiratory motion but also general body motions, analyzes the body motion information obtained by the sensor, and branches and executes processing for subsequent data collection and image reconstruction according to the analysis result.

Abstract: An imaging target site of a subject can be automatically aligned with imaging space, without using additional hardware. A nuclear magnetic resonance signal received by a receiver coil arranged at the imaging target site of the subject is used to calculate a position of the receiver coil. A table on which the subject is placed is moved in a manner to align the position of the receiver coil with the imaging space of the magnetic resonance imaging apparatus. With this configuration, the imaging target site of the subject can be aligned with the imaging space of the magnetic resonance imaging apparatus.

Abstract: The receiving coil device includes one or a plurality of receiving coils configured to cover a head of a subject, a base portion on which the head of the subject is to be placed, a holder portion supported by the base portion, one of the receiving coils being fixed to the holder portion, a mechanism portion configured to bring the receiving coil fixed to the holder portion into close contact with a part of the head, and further, a detection unit configured to detect a physical quantity related to a displacement of the holder portion on the holder portion or the base portion. The physical quantity detected by the detection unit is sent to an MRI apparatus including the receiving coil device.

Abstract: The present invention provides a technique capable of accurately and automatically setting a region of interest for acquiring biological information based on a biological information signal obtained from a subject placed in an examination space in a non-contact manner. A signal analyzing unit of a medical imaging apparatus uses the biological information signal for each of a plurality of regions included in a predetermined range among signals measured by a biological information measuring apparatus to select the region of interest in which movement of the subject is to be acquired among the plurality of regions. The movement of the subject is calculated using the biological information signal measured by the biological information measuring apparatus from the selected region of interest.

Abstract: An imaging target site of a subject can be automatically aligned with imaging space, without using additional hardware. A nuclear magnetic resonance signal received by a receiver coil arranged at the imaging target site of the subject is used to calculate a position of the receiver coil. A table on which the subject is placed is moved in a manner to align the position of the receiver coil with the imaging space of the magnetic resonance imaging apparatus. With this configuration, the imaging target site of the subject can be aligned with the imaging space of the magnetic resonance imaging apparatus.

Abstract: To reduce vibration resulting from applying a gradient magnetic field pulse. A gradient magnetic field coil is supported on a static magnetic field generating device. A control unit generates a gradient magnetic field pulse of a predetermined waveform in the gradient magnetic coil at predetermined timing, and executes a predetermined imaging pulse sequence including the gradient magnetic field pulse. The control unit includes a waveform determination unit determining a waveform of a gradient magnetic field pulse, and the waveform determination unit is configured to determine a waveform of the gradient magnetic field pulse so as to reduce a vibration transmissibility of a propagation path including a support for the gradient magnetic field coil and a table so as to prevent a force generated in the gradient magnetic field coil when a current is passed through the gradient magnetic field coil from being conveyed to the subject by way of the propagation path and fluctuation is caused in the subject's position.

Abstract: In order to provide a static magnetic field homogeneity adjustment method capable of reducing an arrangement amount of magnetic pieces and achieving desired magnetic field homogeneity with high accuracy in magnetic field homogeneity adjustment, there is provided a static magnetic field homogeneity adjustment method in an imaging space of computing positions of a plurality of magnetic pieces separated from the imaging space through shimming computation with respect to a static magnetic field in the imaging space generated by a magnetic field generation device, and disposing the plurality of magnetic pieces at the positions obtained through the shimming computation, the method including an adjustment step of imposing restriction that a polarity of a magnetic field distribution generated in the imaging space by the magnetic pieces disposed at the positions is either positive or negative during the shimming computation, and adjusting the static magnetic field homogeneity.

Abstract: In the present invention, a current plane which is virtually disposed and surrounds a measurement position is assumed from magnetic field measurement values, and a current distribution (or magnetic moment distribution) which mimics a measured magnetic field is reproduced with current potentials. This is used to perform shimming calculation by a truncated singular value decomposition method with discrete shim trays that are actually used and ideal virtual continuous shim trays to carry out shimming under conditions for shimming having a uniformity that is close to ideal shimming.

Abstract: The present invention provides a shimming method in which an electric current surface that is virtually placed so as to surround a measurement position is assumed from a magnetic field measurement value, in which an electric current distribution that reproduces a measurement magnetic field is reproduced through an electric current potential, and in which the reproduced magnetic field distribution is used. A magnetic moment or an electric current distribution that reproduces a magnetic field distribution obtained by a magnetic field measurement device is estimated on a predetermined closed surface, and, from the estimated magnetic moment or electric current distribution, a magnetic field distribution of an arbitrary point that exists in the closed surface is estimated. Then, on the basis of the estimated magnetic field distribution, a shim magnetic body distribution that produces a correction magnetic field for correcting the magnetic field distribution at the arbitrary point is output.

Abstract: A magnetic moment arrangement calculation method for magnetic field adjustment by combining correction of a component of a low-order mode with correction of a component of a high-order mode among the eigenmodes so as to calculate arrangement of the magnetic moment for approximately correcting the error magnetic field distribution, in which the low-order mode is an eigenmode group from the first of eigenmode numbers assigned to respective eigenmodes in the magnitude order of singular values to an eigenmode number specified by a first threshold value, in which the high-order mode is an eigenmode group with an eigenmode number more than the first threshold value, and in which a correction amount of the component of the high-order mode is smaller than a correction amount of the component of the low-order mode.

Abstract: Even if there is a restriction in an amount of magnetic pieces which can be disposed at each position in a shim tray, a distribution of a static magnetic field is measured so that an error magnetic field between the distribution of the static magnetic field and a target magnetic field is calculated, and respective reachable magnetic field homogeneities in a case where the magnetic pieces are disposed at one or more of the plurality of positions in the shim tray are calculated while changing the target magnetic field. The target magnetic field is selected in which an amount of magnetic pieces at each of the positions in the shim tray is equal to or less than a predetermined upper limit value, and the reachable magnetic field homogeneity is equal to or less than a predetermined value.

Abstract: In order to obtain highly accurate images with a high SNR without extending measurement time or increasing hardware costs and software processing costs, the present invention narrows a dynamic range (amplitude) of an NMR signal to be received by a reception coil (reception NMR signal) in an MRI apparatus. In order to narrow the amplitude of the reception NMR signal, according to the position of an imaging region, a peak position of the reception NMR signal is shifted from the said position in the present embodiment. The shift is achieved by applying frequency encoding gradient magnetic field pulses whose application amount in the time direction is different according to the position. This is realized by a plurality of gradient magnetic field generating systems that can be driven independently.

Abstract: Even if there is a restriction in an amount of magnetic pieces which can be disposed at each position in a shim tray, a distribution of a static magnetic field is measured so that an error magnetic field between the distribution of the static magnetic field and a target magnetic field is calculated, and respective reachable magnetic field homogeneities in a case where the magnetic pieces are disposed at one or more of the plurality of positions in the shim tray are calculated while changing the target magnetic field. The target magnetic field is selected in which an amount of magnetic pieces at each of the positions in the shim tray is equal to or less than a predetermined upper limit value, and the reachable magnetic field homogeneity is equal to or less than a predetermined value.

Abstract: The present invention provides a shimming method in which an electric current surface that is virtually placed so as to surround a measurement position is assumed from a magnetic field measurement value, in which an electric current distribution that reproduces a measurement magnetic field is reproduced through an electric current potential, and in which the reproduced magnetic field distribution is used. A magnetic moment or an electric current distribution that reproduces a magnetic field distribution obtained by a magnetic field measurement device is estimated on a predetermined closed surface, and, from the estimated magnetic moment or electric current distribution, a magnetic field distribution of an arbitrary point that exists in the closed surface is estimated. Then, on the basis of the estimated magnetic field distribution, a shim magnetic body distribution that produces a correction magnetic field for correcting the magnetic field distribution at the arbitrary point is output.

Abstract: It is an object of the present invention to provide a technique for reducing the degradation of the image quality due to the phase difference between scanning trajectories (blades) in measurement using a non-orthogonal sampling method. Therefore, in the present invention, correction for reducing the phase difference between a plurality of scanning trajectories (blades) measured by using a non-orthogonal sampling method is performed at the time of image reconstruction. For example, the reduction of the phase difference is performed using a method of matching the phases at the intersections between blades, matching the phases of all blades at positions determined by considering the shift amount in the frequency direction, or canceling out the phase change amount of each blade obtained by calculation.

Abstract: There is provided an MRI apparatus including a superconducting magnet that includes a refrigerant container and a superconducting coil, a cryogenic cooling system with which the superconducting magnet is provided, and a controller that controls the operation of the cryogenic cooling system. The cryogenic cooling system includes a cold head, a cryo-cooler, a compressor that supplies a compressed gas to the cryo-cooler, and a detection unit that detects the pressure in the refrigerant container, the refrigerant container being provided with the cold head, the cryo-cooler, the compressor, and the detection unit. An upper limit value of the maximum number of times of halts of the compressor within a predetermined period of time is set in advance.

Abstract: The present invention obtains high-quality images even in a case of measurement with a radial sampling method. For this purpose, pre-measurement is performed to extract only a component different for each blade from among shift amounts from among echo signals, and a shift amount in k-space of an echo signal by the said component is reflected to a reconstruction process. In the pre-measurement, echo signals are obtained respectively by applying readout gradient magnetic field pulses that change the polarity to the positive and negative and that have the same pulse shape as readout gradient magnetic field pulses to be used in an image acquisition sequence. A shift amount is obtained for each axis of X, Y, and Z of an MRI apparatus as a variation amount of a phase difference between both the echo signals.

Abstract: There is provided an MRI apparatus including a superconducting magnet that includes a refrigerant container and a superconducting coil, a cryogenic cooling system with which the superconducting magnet is provided, and a controller that controls the operation of the cryogenic cooling system. The cryogenic cooling system includes a cold head, a cryo-cooler, a compressor that supplies a compressed gas to the cryo-cooler, and a detection unit that detects the pressure in the refrigerant container, the refrigerant container being provided with the cold head, the cryo-cooler, the compressor, and the detection unit. An upper limit value of the maximum number of times of halts of the compressor within a predetermined period of time is set in advance.