1. A diagnostic imaging apparatus comprising: an ultrasonic probe which transmits ultrasonic waves to a target object and acquires a reflection signal from said target object, for a plurality of image frames which is constituted as two-dimensional ultrasonic image acquired by said ultrasonic probe; a measuring area setting unit which sets, for each image frame, a plurality of measuring areas used for measuring a body movement of said target object, and divides said two-dimensional ultrasonic image into said plurality of measuring areas; a body movement measuring unit which measures body movement and deformation amounts of said target object, in comparison between said measuring areas of a base image frame and said measuring areas of following image frames which follow said base frame in time series; an image accumulating/subtracting unit which accumulates or subtracts a plurality of images of the plurality of said image frames after a body movement correction based on said measurement of said body movement; and an image display unit which displays a reconstructed two-dimensional tomogram image processed by said image accumulating/subtracting unit by using said measuring areas; and wherein, in a pulse inversion mode a higher harmonic wave component is acquired in high S/N ratio by continuous irradiation of a fundamental wave and a reversed phase wave, and by accumulating reflection waves of both, a display image is constituted by carrying out body movement measurement by the wave component obtained by accumulating/subtracting said reflection waves, wherein the measuring area setting unit, the body movement measuring unit, the image accumulating/subtracting unit and the image display unit are at least partially embodied by one or more hardware component.