JP2010167143A5 - - Google Patents

Claims (5)

A static magnetic field generating means, a gradient magnetic field generating means, a high frequency magnetic field pulse irradiating means, a receiving means for receiving a magnetic resonance signal generated from a subject, a signal processing means for reconstructing an image based on the magnetic resonance signal, upper Symbol gradient magnetic field generating means, the high frequency magnetic field pulse irradiation means, in the magnetic resonance imaging apparatus and a control means for executing a photographing sequence by controlling the receiving means and signal processing means,
Pre-measured data corresponding to the time lag between the signal peak of the magnetic resonance signal at a plurality of gradient magnetic field strengths and a plurality of slew rates and the reception timing of the magnetic resonance signal of the receiving means, the gradient magnetic field strength, A storage means for storing each slew rate is provided.
The control means reads the time lag corresponding to the gradient magnetic field strength and slew rate used for imaging from the storage means, and adjusts the gradient magnetic field application timing and the gradient magnetic field area based on the read time lag. A magnetic resonance imaging apparatus. 2. The magnetic resonance imaging apparatus according to claim 1, wherein the control means includes a first time lag between a magnetic resonance signal by a readout gradient magnetic field and a reception timing of the reception means in a first sequence of imaging, and the readout inclination. A second time lag between the magnetic resonance signal by the gradient magnetic field whose polarity is reversed with respect to the magnetic field and the reception timing of the receiving means, a magnetic resonance signal by the gradient magnetic field whose polarity is reversed from the slice selection gradient magnetic field in the second sequence of imaging A third time lag with respect to the reception timing of the receiving means is measured, and a first time lag due to a system response lag from the measured first time lag, second time lag, and third time lag. And a second time delay due to an area error between the dephase gradient magnetic field area and the readout gradient magnetic field area in the first sequence of imaging. And a third time delay due to an area error between the slice selective gradient magnetic field area in the second imaging sequence and the gradient magnetic field area in which the polarity of the slice selective gradient magnetic field area is inverted, and the calculated first time delay A magnetic resonance imaging apparatus characterized in that the second time lag and the third time lag are data corresponding to the time lag. 3. The magnetic resonance imaging apparatus according to claim 2, wherein the control unit includes the second time delay corresponding to the first time lag, the second time lag, and the third time lag from the storage unit, and the third time lag. A correction pulse for correcting the gradient magnetic field area from the read second time delay and third time delay, and adjusting the application timing of the gradient magnetic field based on the first time delay, A magnetic resonance imaging apparatus, wherein the area error is corrected by applying the calculated correction pulse to a gradient magnetic field.   The magnetic resonance imaging apparatus according to claim 1, wherein the data corresponding to the time lag is a first time lag between a magnetic resonance signal due to a readout gradient magnetic field and a reception timing of the receiving means in a first sequence of imaging, Due to a second time lag between the magnetic resonance signal due to the gradient magnetic field whose polarity is reversed with respect to the readout gradient magnetic field and the reception timing of the receiving means, and due to the gradient magnetic field whose polarity is reversed with respect to the slice selection gradient magnetic field in the second sequence of imaging. A magnetic resonance imaging apparatus, characterized by a third time lag between the magnetic resonance signal and the reception timing of the receiving means.   5. The magnetic resonance imaging apparatus according to claim 4, wherein the control means detects a first time due to a system response delay from a first time lag, a second time lag, and a third time lag read from the storage means. The second time delay due to the delay, the area error between the dephase gradient magnetic field area and the readout gradient magnetic field area in the first sequence of imaging, the slice selective gradient magnetic field area and the slice selective gradient magnetic field surface in the second sequence of imaging A third time delay due to an area error with the gradient magnetic field area in which the aggressiveness is reversed is calculated, a correction pulse for correcting the gradient magnetic field area is calculated from the calculated second time delay and the third time delay, Based on the time delay of 1, the gradient magnetic field application timing is adjusted, and the area error is compensated by applying the calculated correction pulse to the gradient magnetic field. Magnetic resonance imaging apparatus characterized by.