MRI apparatus

An MRI apparatus comprising:

• a gradient coil configured to superimpose a gradient magnetic field on a static magnetic field;
• a receiving circuit configured to receive an MR (magnetic resonance) signal from an object placed in the gradient magnetic field;
• and
• processing circuitry configured to
• estimate time variation of an MR (magnetic resonance) frequency during a sampling period in which a readout gradient is applied for sampling the received MR signal based on waveform data of a gradient current applied to the gradient coil,
• perform correction on a frequency or phase of the received MR signal received by the receiving circuit during the sampling period in which the readout gradient is applied, based on the estimated time variation of the MR frequency during the sampling period, and
• reconstruct an image by using the MR signal subjected to the correction, wherein
• the receiving circuit includes a detector configured to detect the MR signal;
• the processing circuitry is configured to control the receiving circuit in such a manner that a frequency or phase of the MR signal outputted from the detector is corrected according to the estimated time variation of the MR frequency during the sampling period, and reconstruct an image by using the MR signal after correction that are outputted from the detector;
• the receiving circuit further includes a synthesizer configured to output a reference signal corresponding to the estimated time variation of the MR frequency, the reference signal being used in the detector for detecting the received MR signal, and
• the detector is configured to correct variation in frequency or phase of the MR signal by using the reference signal.