A diagnostic imaging apparatus includes a ventricular volume-variation measuring unit that measures sequential variations in a size of a ventricle within at least one heart beat, from images of a heart scanned in each of a plurality of time phases a scanning-condition setting unit that specifies a time phase of little cardiac motion based on variations in the size of the ventricle measured by the ventricular volume-variation measuring unit, and sets scanning conditions so as to collect data in the specified time phase and an imaging unit that collects data based on the scanning conditions set by the scanning-condition setting unit, and reconstructs an image from the collected data.
