A magnetization vector is detected for each pixel position in an imaging region including at least part of a subject, the magnetization vector being excited to have a phase difference between a flow portion and a static portion or between a normal portion and an abnormal portion. A pixel value at each pixel position is determined as a value proportional to an absolute value of the amplitude of the magnetization vector detected for each of the pixel positions. On s the basis of a real part or phase of the magnetization vector detected for each of the pixel positions, the determined pixel value is corrected so that the difference of the pixel value increases between (a) the flow portion or the abnormal portion and (b) the static portion or the normal portion.