PROBLEM TO BE SOLVED: To provide an MRI apparatus and a method which can extract two tissues or one of them in a portion with respect to the other at high luminance without prolonging a pulse application time.SOLUTION: An imaging part of an MRI apparatus uses a high frequency pulse including a preliminary RF pulse exciting a first region and an excitation RF pulse exciting a second region different from the first region to collect NMR signals. A shimming parameter calculation part calculating a shimming parameter that adjusts irradiation magnetic field distribution generated by the high frequency pulse radiated by a plurality of channels sets different shimming parameters respectively for the preliminary RF pulse and the excitation RF pulse, and an imaging part uses the preliminary RF pulse and the excitation RF pulse adjusted by a different shimming parameter to perform imaging.SELECTED DRAWING: Figure 6
