Patent ID: 7868618

Claim:
A magnetic resonance imaging apparatus comprising a means for generating a static magnetic field, a means for generating a magnetic field gradient to be superimposed on the static magnetic field, a means for irradiating an excitation RF pulse on a test subject placed in the static magnetic field, a means for detecting nuclear magnetic resonance signals emitted from the test subject, a means for reconstructing an image from the nuclear magnetic resonance signals, and a means for controlling the means for irradiating an excitation RF pulse and the means for detecting nuclear magnetic resonance signals so as to execute a non-imaging mode in which a nuclear magnetic resonance signal is not measured after irradiation of an excitation RF pulse, and an imaging mode in which a nuclear magnetic resonance signal is measured after irradiation of an excitation RF pulse, wherein: the means for irradiating an excitation RF pulse changes flip angle of nuclear magnetization in the imaging mode in a range of values not larger than a certain value defined by a flip angle of nuclear magnetization used in the non-imaging mode; the means for irradiating an excitation RF pulse substantially continuously modulates flip angle of nuclear magnetization in the imaging mode; and the means for irradiating an excitation RF pulse modulates flip angle of nuclear magnetization in one time of imaging in the imaging mode so that flip angle at the beginning of the imaging and flip angle at the end of the imaging should be the same or substantially the same.