Magnetic resonance imaging apparatus and magnetic resonance imaging method

1. A magnetic resonance imaging apparatus comprising:

an imaging condition setting unit configured to set an imaging sequence for acquiring imaging data, a dummy shot sequence prior to the imaging sequence, a correction use sequence and an acoustic control sequence, the imaging condition setting unit including:

an acoustic control unit configured to set the dummy shot sequence and the acoustic sequence such that the dummy shot sequence is performed in synchronization with a signal representing a respiratory body motion, while applying an excitation pulse together with a slice selection gradient, the excitation pulse and a repetition time thereof in the dummy shot sequence being the same as those in the imaging sequence,

wherein the acoustic control sequence is performed by adding a gradient magnetic field for an acoustic control to the correction use sequence;

a correction data acquisition unit configured to acquire, in a period of the dummy shot sequence, correction use data or correcting an influence of a respiratory body motion on image data in synchronization with a signal representing the respiratory body motion, the correction use data being two-dimensional image data with a low resolution in an X-axis and a Y-axis direction;

an adjusting unit configured to adjust the period of the dummy shot sequence so as to keep a repetition time for acquiring the imaging data constant;

a data acquisition unit configured to acquire imaging data for imaging subsequently to acquiring the correction use data; and

a correction unit configured to generate image data by correcting the influence of the respiratory body motion based on a position shift in each of the X-axis and Y-axis directions in the correction use data.

2. The magnetic resonance imaging apparatus of claim 1 , wherein said acoustic control unit is configured to control at least one of a frequency and an intensity of the gradient magnetic field in accordance with the signal representing the respiratory body motion.

3. The magnetic resonance imaging apparatus of claim 1 , wherein said acoustic control unit is configured to control at least one of a frequency and an intensity of the gradient magnetic field in accordance with a temporal variation of a periodical interval of the signal representing the respiratory body motion.

4. The magnetic resonance imaging apparatus of claim 1 , wherein said acoustic control unit is configured to control at least one of a frequency and an acoustic pressure of the sound in accordance with a variation of a gain for adjusting a level of the signal representing the respiratory body motion.

5. The magnetic resonance imaging apparatus of claim 1 , wherein said acoustic control unit is configured to control the sound by adjusting a frequency of the gradient magnetic field.

6. The magnetic resonance imaging apparatus of claim 1 , wherein said acoustic control unit is configured to control the sound by adjusting a shape of an envelope formed by the gradient magnetic field.

7. The magnetic resonance imaging apparatus of claim 1 , wherein said a correction data acquisition unit is configured to acquire the correction use data according to an echo planar imaging sequence.

8. The magnetic resonance imaging apparatus of claim 1 , wherein said a correction data acquisition unit is configured to acquire the correction use data according to a fast field echo sequence.

9. The magnetic resonance imaging apparatus of claim 1 , wherein said a correction data acquisition unit is configured to acquire the correction use data while applying a gradient magnetic field for frequency encode having a frequency higher than a frequency of a gradient magnetic field for frequency encode applied for acquiring the imaging data.

10. The magnetic resonance imaging apparatus of claim 1 , wherein said correction data acquisition unit is configured to acquire the correction use data as either of (a) information regarding the respiratory body motion and (b) information regarding a phase of the imaging data.

11. The magnetic resonance imaging apparatus of claim 1 , further comprising:

an adjusting unit configured to adjust a period for acquiring the correction use data in accordance with the signal representing the respiratory body motion while keeping the repetition time for acquiring the imaging data constant.

12. A magnetic resonance imaging method comprising:

setting an imaging sequence for acquiring imaging data, a dummy shot sequence prior to the imaging sequence, a correction use sequence and an acoustic control sequence;

setting the dummy shot sequence and the acoustic sequence such that;

the dummy shot sequence is performed in synchronization with a signal representing a respiratory body motion, while applying a excitation pulse together with a slice selection gradient, the excitation pulse and a repetition time thereof in the dummy shot sequence being same as those in the imaging sequence,

the acoustic control sequence is performed by adding a gradient magnetic field for an acoustic control to the correction use sequence;

acquiring, in a period of the dummy shot sequence, correction use data for correcting an influence of a respiratory body motion on image data in synchronization with a signal representing the respiratory body motion, the correction use data being two-dimensional image data with a low resolution in an X-axis and a Y-axis direction;

adjusting the period of the dummy shot sequence so as to keep a repetition time for acquiring the imaging data constant;

acquiring imaging data by imaging subsequently to acquiring the correction use data; and

generating image data by correcting the influence of the respiratory body motion based on a position shift in each of the X-axis and Y-axis directions in the correction use data.