Abstract: In one embodiment, an MRI apparatus includes a gradient coil, a receiving circuit, and processing circuitry. The gradient coil is configured to superimpose a gradient magnetic field on a static magnetic field. The receiving circuit is configured to receive an MR (magnetic resonance) signal from an object placed in the gradient magnetic field. The processing circuitry is configured to estimate time variation of an MR (magnetic resonance) frequency during a sampling period of the MR signal based on waveform data of a gradient current applied to the gradient coil, perform correction on a frequency or phase of the MR signal received by the receiving circuit based on the estimated time variation of the MR frequency during the sampling period, and reconstruct an image by using the MR signal subjected to the correction.

Abstract: In one embodiment, an MRI apparatus includes: a scanner equipped with at least a static magnetic field magnet, a gradient coil, and an RF coil configured to apply RF pulses to an object and receive magnetic resonance signals from the object; and processing circuitry configured to set a pulse sequence in which refocusing pulses are sequentially applied subsequent to application of one excitation pulse and a predetermined number of magnetic resonance signals are acquired in each period between adjacent two refocusing pulses by using a water/fat separation method, such that the magnetic resonance signals are different in echo time TE for each of the plurality of refocusing pulses, cause the scanner to acquire the magnetic resonance signals under the pulse sequence, and generate a computed image from the magnetic resonance signals, the computed image being a magnetic resonance image of the object obtained by computation.

Abstract: In one embodiment, an MRI apparatus (20) includes a reference scan setting unit (100), a reference scan execution unit, and an image generation unit. The reference scan setting unit calculates a signal acquisition region of “a reference scan in which MR signals used for generation of a sensitivity distribution map of each coil element are acquired”, depending on an imaging region of a main scan of parallel imaging. The reference scan execution unit executes the reference scan on the calculated signal acquisition region. The image generation unit generates image data according to “MR signals acquired by the main scan” and “the sensitivity distribution map generated based on MR signals acquired by the reference scan”.

Abstract: In one embodiment, an MRI apparatus includes a gradient generation circuit configured to apply a gradient pulse according to a pulse sequence in which application of an RF pulse and application of the gradient pulse are included; and an RF transmission circuit configured to (a) perform modulation on a controlled output waveform of the RF pulse in such a manner that the controlled output waveform of the RF pulse follows time variation of a magnetic resonance frequency caused by time variation of an eddy-current magnetic field estimated from a waveform of the gradient pulse and (b) apply the RF pulse subjected to the modulation to an object.

Abstract: In one embodiment, an MRI apparatus includes a gradient coil, a receiving circuit, and processing circuitry. The gradient coil is configured to superimpose a gradient magnetic field on a static magnetic field. The receiving circuit is configured to receive an MR (magnetic resonance) signal from an object placed in the gradient magnetic field. The processing circuitry is configured to estimate time variation of an MR (magnetic resonance) frequency during a sampling period of the MR signal based on waveform data of a gradient current applied to the gradient coil, perform correction on a frequency or phase of the MR signal received by the receiving circuit based on the estimated time variation of the MR frequency during the sampling period, and reconstruct an image by using the MR signal subjected to the correction.

Abstract: Magnetic resonance imaging (MRI) is configured to carry out sequential imaging, to acquire an actual SAR measurement value at a predetermined timing during the sequential imaging, and to update a subsequent predicted SAE value each time the actual SAR measurement value is acquired.

Abstract: According to one embodiment, a medical image diagnostic apparatus includes a display and processing circuitry. The display displays a relationship diagram indicating a relationship between values which are respectively set for imaging parameters relating to an imaging condition of medical imaging. The processing circuitry updates the relationship diagram in accordance with a moving operation of a point corresponding to each of the values on the relationship diagram, or a change operation of the imaging condition. The processing circuitry changes the imaging condition before the moving operation or the change operation to an imaging condition which reflects the moving operation or the change operation.

Abstract: In one embodiment, an MRI apparatus includes: a scanner equipped with at least a static magnetic field magnet, a gradient coil, and an RF coil configured to apply RF pulses to an object and receive magnetic resonance signals from the object; and processing circuitry configured to set a pulse sequence in which refocusing pulses are sequentially applied subsequent to application of one excitation pulse and a predetermined number of magnetic resonance signals are acquired in each period between adjacent two refocusing pulses by using a water/fat separation method, such that the magnetic resonance signals are different in echo time TE for each of the plurality of refocusing pulses, cause the scanner to acquire the magnetic resonance signals under the pulse sequence, and generate a computed image from the magnetic resonance signals, the computed image being a magnetic resonance image of the object obtained by computation.

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a processor and a memory. The memory stores processor-executable instructions that, when executed by the processor, cause the processor to receive an operation of setting an application condition concerning a local excitation pulse that is a radio frequency (RF) pulse for local excitation applied to a local region different from an imaging region; generate a waveform of the local excitation pulse based on the application condition; and set an imaging condition such that an index value calculated from the waveform of the local excitation pulse does not exceed a limit value.

Abstract: A magnetic resonance imaging apparatus of an embodiment includes: an imaging condition setting section configured to set an imaging condition for a main scan, a preparatory scan performing section configured to repeat a preparatory scan to be performed by the use of the imaging condition for a main scan and a changeably inputted center frequency so as to generate a preparatory image in real time, a display section on which the preparatory image can be displayed in real time, an optimum center frequency setting section configured to change the center frequency so as to change a situation in which a banding artifact appears and configured to set an optimum center frequency according to a user operation based on an observation of the preparatory image, and a main scan performing section configured to reconstruct an image for a diagnosis by using the optimum center frequency having been set.

Abstract: In one embodiment, an MRI apparatus (10) includes a gap calculating unit (65), a candidate calculating unit (66) and a sequence setting unit (61). The gap calculating unit calculates a gap between the center frequency of an RF pulse and a resonance center frequency, after start of a pulse sequence. The candidate calculating unit calculates a plurality of candidate timings so as to avoid influence of a CF scan for measuring the resonance center frequency on MR signals, when the CF scan is inserted in the pulse sequence. The sequence setting unit sets the pulse sequence so that CF scans are inserted in the pulse sequence at the timings according to the gap and the candidate timings. Each time the CF scan is executed, the center frequency of an RF pulse is updated and the pulse sequence is continued. Thereby, the MR signals are acquired.

Abstract: In one embodiment, an MRI apparatus includes a gradient generation circuit configured to apply a gradient pulse according to a pulse sequence in which application of an RF pulse and application of the gradient pulse are included; and an RF transmission circuit configured to (a) perform modulation on a controlled output waveform of the RF pulse in such a manner that the controlled output waveform of the RF pulse follows time variation of a magnetic resonance frequency caused by time variation of an eddy-current magnetic field estimated from a waveform of the gradient pulse and (b) apply the RF pulse subjected to the modulation to an object.

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a sequence control unit that controls a gradient magnetic field power supply, thereby performing a pulse sequence including the application of a continuous readout gradient magnetic field pulse. The sequence control unit controls the gradient magnetic field power supply such that the slew rate of the gradient magnetic field pulse is reduced in stages as the output voltage of a gradient magnetic field amplifier is reduced in stages.

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a processor and a memory. The memory stores processor-executable instructions that, when executed by the processor, cause the processor to receive an operation of setting an application condition concerning a local excitation pulse that is a radio frequency (RF) pulse for local excitation applied to a local region different from an imaging region; generate a waveform of the local excitation pulse based on the application condition; and set an imaging condition such that an index value calculated from the waveform of the local excitation pulse does not exceed a limit value.

Abstract: An MRI apparatus comprising: an imaging unit configured to carry out sequential imaging; an SAR acquisition unit configured to acquire an actual SAR measurement value at a predetermined timing during the sequential imaging; and a prediction unit configured to update a subsequent predicted SAE value each time the actual SAR measurement value is acquired.

Abstract: In one embodiment, an MRI apparatus (10) includes a gap calculating unit (65), a candidate calculating unit (66) and a sequence setting unit (61). The gap calculating unit calculates a gap between the center frequency of an RF pulse and a resonance center frequency, after start of a pulse sequence. The candidate calculating unit calculates a plurality of candidate timings so as to avoid influence of a CF scan for measuring the resonance center frequency on MR signals, when the CF scan is inserted in the pulse sequence. The sequence setting unit sets the pulse sequence so that CF scans are inserted in the pulse sequence at the timings according to the gap and the candidate timings. Each time the CF scan is executed, the center frequency of an RF pulse is updated and the pulse sequence is continued. Thereby, the MR signals are acquired.

Abstract: A magnetic resonance imaging apparatus of an embodiment includes: an imaging condition setting section configured to set an imaging condition for a main scan, a preparatory scan performing section configured to repeat a preparatory scan to be performed by the use of the imaging condition for a main scan and a changeably inputted center frequency so as to generate a preparatory image in real time, a display section on which the preparatory image can be displayed in real time, an optimum center frequency setting section configured to change the center frequency so as to change a situation in which a banding artifact appears and configured to set an optimum center frequency according to a user operation based on an observation of the preparatory image, and a main scan performing section configured to reconstruct an image for a diagnosis by using the optimum center frequency having been set.

Abstract: The temperature of an MRI gradient magnetic field coil unit is measured at least two times. Shift data indicating a center magnetic resonance frequency of a hydrogen atom in response to variation of the gradient coil temperature is stored in advance. Estimated shift of the center frequency based on the measurement result is determined and the center frequency of an RF NMR excitation pulse is corrected based on the estimated shift.

Abstract: According to one embodiment, an MRI apparatus performs magnetic resonance imaging under a gradient magnetic field by providing a gradient magnetic field generation system with electric current so as to apply the gradient magnetic field on an imaging region. This MRI apparatus includes a condition setting unit and a load acquisition unit. The condition setting unit sets imaging conditions of the magnetic resonance imaging. The load acquisition unit acquires information on a waveform of the gradient magnetic field, and calculates respective electric loads for a plurality of frequency bands imposed on the gradient magnetic field generation system in a case of performance of the magnetic resonance imaging, based on the information on a waveform.

Abstract: According to one embodiment, an MRI apparatus (20) performs magnetic resonance imaging under a gradient magnetic field by providing a gradient magnetic field generation system with electric current so as to apply the gradient magnetic field on an imaging region. This MRI apparatus includes a condition setting unit (100) and a load acquisition unit (104). The condition setting unit sets imaging conditions of the magnetic resonance imaging. The load acquisition unit acquires information on a waveform of the gradient magnetic field, and calculates respective electric loads for a plurality of frequency bands imposed on the gradient magnetic field generation system in a case of performance of the magnetic resonance imaging, based on the information on a waveform.