1. A magnetic resonance imaging apparatus comprising, an imaging means for applying an RF magnetic field and a magnetic field gradient to a subject placed in a static magnetic field and for detecting a magnetic resonance signal generated from the subject, a calculation means for processing the signal, and a control means for controlling the imaging means and the calculation means, wherein, the control means exercises control to perform a process including the steps of; (1) obtaining first images at different positions in a first direction, (2) obtaining images by correcting brightness distortion of the first images, (3) obtaining images by correcting positional distortion of the images as to which the brightness distortion has been corrected, and (4) synthesizing by a weighting calculation, overlapping areas of the images as to which the positional distortion has been corrected.