A velocity-image creating unit creates a velocity image that indicates a distribution of velocity components with respect to each of a plurality of images obtained by repeating a plurality of number of times Echo Planar Imaging (EPI) that is capable of obtaining velocity components of a Cerebrospinal Fluid (CSF) flowing inside a subject. A velocity-variance image creating unit calculates variance of velocity components along the time sequence by same position on velocity images by using a plurality of created velocity images. A superimposed-image processing unit then superimposes the distribution of the variance of the velocity components according to the velocity-variance image on an average absolute-value image, and an image display unit displays a superimposed image.