An embodiment relates to an image processing apparatus and a magnetic resonance imaging apparatus. The invention provides a an image processing apparatus and a magnetic resonance imaging apparatus capable of properly evaluating a dynamic image of the fluid in an article to be detected. The image processing apparatus according to an embodiment includes a specifying unit and a deriving unit. The specifying unit specifies a fluid region in a plurality of magnetic resonance images that are acquired by applying a labeling pulse to a label region and that are mutually related. The deriving unit derives an index indicating dynamics of a fluid on the basis of the specified fluid region.