An ultrasound diagnostic apparatus according to an embodiment includes processing circuitry and controlling circuitry. The processing circuitry is configured to generate brightness transition information indicating a temporal transition of a brightness level in an analysis region that is set in an ultrasound scan region, from time-series data acquired by performing an ultrasound scan on a subject to whom a contrast agent has been administered and to obtain a parameter by normalizing reflux dynamics of the contrast agent in the analysis region with respect to time, based on the brightness transition information. The controlling circuitry is configured to cause a display to display the parameter in a format using one or both of an image and text.
