Patent ID: 7696753

Claim:
A magnetic resonance imaging (MRI) apparatus comprising: an MRI data collecting unit which collects data for a plurality of average units, each average unit including template magnetic resonance (MR) data without performing phase encoding using switched gradient magnetic fields, and MR imaging data with phase encoding using switched gradient magnetic fields; a calculating unit which calculates a frequency difference between a resonant frequency in a reference average unit and an object average unit based on a phase variation of MR signals (a) in a period where the template data is collected in the reference average unit and (b) in a period where the template data is collected in the object average unit, wherein (i) if the number of average units is two, the reference average unit is one of the average units, and the object average unit is the other one of the average units, and (ii) if the number of average units is three or more, the reference average unit is one of the average units, and the object average unit is constituted by remaining ones of the average units; a correcting unit which corrects a ΔB 0 —induced phase shift in the direction of an applied phase encoding gradient magnetic field in image data collected in the object average unit constituted by one or more average units based on the frequency difference calculated for the average unit; and a reconstructing unit which reconstructs an image concerning the subject based on MR imaging data collected in the reference average unit and the MR imaging data of the object average unit constituted by one or more average units corrected by the correcting unit.