Abstract: Provided are MRI images with excellent image quality and in which the occurrence of artifacts is suppressed by effectively removing a secondary error magnetic field, generated by compensation current (additional current), of eddy current that is caused by applying a gradient magnetic field. The present invention measures and analyzes, in advance, a secondary error magnetic field generated due to the applying of compensation current and saves the results as compensation parameters (secondary compensation parameters), uses the secondary compensation parameters to calculate a correction magnetic field output to be applied to each of a gradient magnetic field coil and a correction coil, and supplies this correction magnetic field output to the gradient magnetic field coil and the correction coil to compensate for (cancel out) the secondary error magnetic field.

Abstract: The present invention is directed to enabling high-accuracy Nyquist ghost correction without using a reference image. After at least one of a plurality of images for use in diagnosis is used to perform low-order phase correction without causing aliasing of an image, a 2D phase map including remaining high-order phase errors and phase errors in a phase encode direction is calculated. The low-order phase correction is performed on a pair of pieces of data for image obtained by inverting a readout gradient magnetic field as image data for use in 2D phase map calculation, and positive-polarity/negative-polarity errors of the readout gradient magnetic field are calculated with odd lines and even lines of the pair of pieces of data for image rearranged. In the case of DWI imaging, an image with b-value=0 can be used for 2D phase map calculation.

Abstract: Provided are MRI images with excellent image quality and in which the occurrence of artifacts is suppressed by effectively removing a secondary error magnetic field, generated by compensation current (additional current), of eddy current that is caused by applying a gradient magnetic field. The present invention measures and analyzes, in advance, a secondary error magnetic field generated due to the applying of compensation current and saves the results as compensation parameters (secondary compensation parameters), uses the secondary compensation parameters to calculate a correction magnetic field output to be applied to each of a gradient magnetic field coil and a correction coil, and supplies this correction magnetic field output to the gradient magnetic field coil and the correction coil to compensate for (cancel out) the secondary error magnetic field.

Abstract: The present invention is directed to enabling high-accuracy Nyquist ghost correction without using a reference image. After at least one of a plurality of images for use in diagnosis is used to perform low-order phase correction without causing aliasing of an image, a 2D phase map including remaining high-order phase errors and phase errors in a phase encode direction is calculated. The low-order phase correction is performed on a pair of pieces of data for image obtained by inverting a readout gradient magnetic field as image data for use in 2D phase map calculation, and positive-polarity/negative-polarity errors of the readout gradient magnetic field are calculated with odd lines and even lines of the pair of pieces of data for image rearranged. In the case of DWI imaging, an image with b-value=0 can be used for 2D phase map calculation.