1. A magnetic resonance imaging apparatus configured to generate a static magnetic field, to superpose, on the static magnetic field, a gradient magnetic field generated by a gradient magnetic-field coil, to detect a magnetic resonance signal generated in a subject lying in the static magnetic field and induced from a high-frequency magnetic field emanating from a transmitting coil, and to acquire an image from the magnetic resonance signal, the apparatus comprising: a cine-imaging unit which collects time-series images of an region of interest in the subject and which reconstructs an image; a characterizing-part detecting unit which detects characteristics of the time-series images; a motion-analyzing unit which analyzes motion-characteristic values of the characteristics detected by the characterizing-part detecting unit; and an information-extracting unit which extracts information about a specified time phase, on the basis of the motion-characteristic values.