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: In order to obtain a highly reliable image with no image distortion or no artifacts, such as ghosting, by compensating for the distortion of an output gradient magnetic field waveform caused by various factors with high accuracy, an input gradient magnetic field waveform and an output gradient magnetic field waveform corresponding to the input gradient magnetic field waveform are calculated, a response function that is a sum of response functions of a plurality of elements affecting the output gradient magnetic field waveform is calculated using the input gradient magnetic field waveform and the output gradient magnetic field waveform, an output gradient magnetic field waveform is calculated from an input gradient magnetic field waveform of a gradient magnetic field pulse set in the imaging sequence using the response function, and various kinds of correction are performed using the calculated value of the calculated output gradient magnetic field waveform.

Abstract: In order to obtain a high-quality image even in multi-slice imaging in a UTE sequence that uses a half RF pulse, a refocusing pulse of the slice gradient magnetic field is adjusted and applied so that the excitation profiles of positive polarity data and negative polarity data have phase distributions that are 180 [deg] inverted with respect to each other in side lobe portions. In addition, the irradiation frequency of the half RF pulse is adjusted so as to eliminate a position shift between the intensity distributions of the positive polarity data and the negative polarity data.

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: In order to improve image quality while reducing an SAR regardless of an imaging condition such as a slice position, a phase-encoding amount, and an RF pulse type difference, the VERSE method determines a VERSE pulse compression rate according to the imaging condition. Hence, an imaging sequence generation section generating an imaging sequence by applying an imaging condition to a predetermined pulse sequence and an imaging section executing measurement according to the imaging sequence to reconstruct an image from the obtained echo signal are provided. The pulse sequence includes a VERSE pulse comprised of a high-frequency magnetic field pulse and a slice selective gradient magnetic field pulse. The imaging sequence generation section is provided with a VERSE pulse design part determining a compression rate of the VERSE pulse according to the predetermined imaging condition and applies the determined compression rate to generate the imaging sequence.

Abstract: In order to obtain a high-quality image even in multi-slice imaging in a UTE sequence that uses a half RF pulse, a refocusing pulse of the slice gradient magnetic field is adjusted and applied so that the excitation profiles of positive polarity data and negative polarity data have phase distributions that are 180 [deg] inverted with respect to each other in side lobe portions. In addition, the irradiation frequency of the half RF pulse is adjusted so as to eliminate a position shift between the intensity distributions of the positive polarity data and the negative polarity data.

Abstract: In order to obtain a highly reliable image with no image distortion or no artifacts, such as ghosting, by compensating for the distortion of an output gradient magnetic field waveform caused by various factors with high accuracy, an input gradient magnetic field waveform and an output gradient magnetic field waveform corresponding to the input gradient magnetic field waveform are calculated, a response function that is a sum of response functions of a plurality of elements affecting the output gradient magnetic field waveform is calculated using the input gradient magnetic field waveform and the output gradient magnetic field waveform, an output gradient magnetic field waveform is calculated from an input gradient magnetic field waveform of a gradient magnetic field pulse set in the imaging sequence using the response function, and various kinds of correction are performed using the calculated value of the calculated output gradient magnetic field waveform.