Toshiba Medical Systems Corporation

Canon Medical Systems Corporation

Kabushiki Kaisha Toshiba

Canon Medical Systems Coprporation

Yutaka Machii

Hiroshi Kusahara

Yoshimori Kassai

Naoyuki Furudate

Sho Kawajiri

Motohiro Miura

Yuki Takai

Masashi Hori

Masaaki Nagashima

Takashi Shigeta

According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry sets imaging parameters for each scan. The processing circuitry specifies the size of the object region in the phase encode direction from a first image. The first image acquired by using a pulse sequence different from EPI. The processing circuitry sets parameters in a field of view in the phase encode direction in a phase correction scan based on the specified size and the size of the field of view in the phase encode direction in a second scan. The phase correction scan is executed for acquiring phase correction information for the first image. The second scan is executed for acquiring a second image by using EPI.

Magnetic resonance imaging apparatus

A magnetic resonance imaging apparatus according to an embodiment includes a temperature sensor and a processing circuit. The temperature sensor acquires a temperature. The processing circuit calculates, based on information on an imaging sequence in which magnetic resonance imaging is to be performed, an estimated value of consumption energy of a gradient coil in a case when the imaging sequence is executed and calculates, based on the temperature acquired by the temperature sensor and the estimated value of the consumption energy, an estimated value of a temperature of the gradient coil, the temperature of the gradient coil undergoing changes as the imaging sequence is executed.

Magnetic resonance imaging apparatus and magnetic resonance imaging method

According to one embodiment, a magnetic resonance imaging apparatus includes a gradient coil, power supply circuitry, and control circuitry. The gradient coil generates a gradient magnetic field. The power supply circuitry supply power to the gradient coil, the power being required by the gradient. The control circuitry temporarily change an upper limit value of power to be supplied by the power supply circuitry to a second value higher than a first value as a rated value based on the power required by the gradient coil.

Magnetic resonance imaging apparatus and gradient power supply apparatus

A magnetic resonance imaging apparatus according to an embodiment includes a processing circuit and a sequence control circuit. The processing circuit calculates, based on an imaging sequence to be executed in magnetic resonance imaging, a value of a current flowing through a closed circuit by using an equivalent circuit and determines, prior to an execution of the imaging sequence, based on the value of the current, whether it is acceptable to execute the imaging sequence. The sequence control circuit executes the imaging sequence. The equivalent circuit is an equivalent circuit for a circuit that includes a gradient coil and that has a first circuit and a second circuit. The first circuit is connected to a power supply and has self-inductance. The second circuit includes at least one closed circuit having mutual inductance with the first circuit.

Magnetic resonance imaging apparatus to calculate current in an equivalent circuit including a gradient coil

According to one embodiment, a magnetic resonance imaging apparatus includes a gradient magnetic field power supply, a voltmeter, and processing circuitry. The gradient magnetic field power supply includes an amplifier amplifying an input signal based on information of a gradient magnetic field waveform and outputting the amplified input signal to a gradient coil, a power supply device supplying power to the amplifier, and a capacitor bank supplying power, together with the power supply device, to the amplifier. The voltmeter measures a voltage of the capacitor bank. The processing circuitry calculates frequency characteristics of an impedance of the gradient coil, based on a voltage variation of the capacitor bank which was measured by the voltmeter, and controls imaging in accordance with the calculated frequency characteristics.

A magnetic resonance imaging apparatus according to one embodiment includes a sequence controller, a correction map generator, an image generator, and a corrector. The sequence controller executes first data acquisition to acquire data for a phase correction map, and second data acquisition to acquire data of a cluster of images corresponding to a plurality of time phases. The correction map generator generates the phase correction map by using echo signals acquired through the first data acquisition. The image generator generates the cluster of images corresponding to the time phases by using echo signals acquired through the second data acquisition. The corrector corrects a phase of each image included in the cluster of images, based on the phase correction map and changes in phase of echo signals that occur between time phases.

Magnetic resonance imaging apparatus and method correcting phases in images corresponding to a plurality of time phases

A control device of a magnetic resonance (MRI) imaging apparatus includes a condition setting unit and a judging unit. The condition setting unit sets an imaging sequence to be performed by the magnetic resonance imaging apparatus based on set conditions of the set imaging sequence. The judging unit then (a) calculates a value of electric current supplied to a gradient magnetic field coil of the MRI apparatus to perform that set imaging sequence based on the set conditions of the set imaging sequence, (b) calculates a value of voltage that would need to be applied to the gradient magnetic field coil based on a mutual inductance of the gradient magnetic field to cause electric current flowing to the gradient magnetic field coil to become equal to the value of the calculated electric current, and (c) judges whether the set imaging sequence is practicable or not based on the calculated value of voltage.

Magnetic resonance imaging apparatus and control device of a magnetic resonance imaging apparatus

According to one embodiment, an MRI apparatus includes a gradient coil, an RF coil, an RF receiver, and processing circuitry which controls these components to perform each pulse sequence. The processing circuitry sets a main-scan pulse sequence, a first pulse sequence which includes application of a gradient magnetic field in a readout direction, and a second pulse sequence which includes application of the gradient magnetic field in a readout direction, and whose acquisition region is shifted from the first pulse sequence. The processing circuitry reconstructs image data of the main scan, based on magnetic resonance signals acquired by the main-scan pulse sequence and phase difference data in the readout direction between first k-space data generated from the magnetic resonance signals acquired by the first pulse sequence and second k-space data generated from the magnetic resonance signals acquired by the second pulse sequence.

An MRI apparatus produces a plurality of echo signals by performing an EPI echo signal acquisition sequence including gradient magnetic fields in a phase encoding direction, and acquires a plurality of echo signals as first and second template data, respectively. The second template data is acquired using a sequence in which start timing of a gradient magnetic field in a readout direction is shifted from the case where acquisition of the first template data is performed. The phase error included in the echo signals is corrected by using the first and second template data.

According to one embodiment, a magnetic resonance imaging apparatus includes an imaging unit and a strain correction unit. The imaging unit is configured to acquire frames of diffusion weighted image data corresponding to different b-values by diffusion weighted imaging with applying MPG pulses corresponding to the different b-values of which application axes are same. The strain correction unit is configured to calculate a strain correction coefficient for diffusion weighted image data to be a target of a strain correction based on diffusion weighted image data corresponding to a b-value different from a b-value corresponding to the diffusion weighted image data to be the target of the strain correction among the frames of the diffusion weighted image data to generate image data after the strain correction by the strain correction of the diffusion weighted image data to be the target of the strain correction using the calculated strain correction coefficient.

Growing community of inventors

Nasushiobara, Japan

Yutaka Machii