1. A blood flow dynamic analysis apparatus for use in analyzing kinetics of blood flow in a subject after a contrast medium has been injected into the subject, the blood flow dynamic analysis apparatus comprising: a map generation device configured to compute a value of a parameter related to time change in a concentration of the contrast medium injected into the subject and to generate a map of the parameter; and a display condition determination device configured to determine a display condition for the map based on a threshold value of the parameter for discriminating between a lesion region where a lesion exists and an unaffected region where no lesion exists in the map.