The invention relates to an ultrasonic imaging system for diagnostic use or non-destructive testing. The system comprises a first array of ultrasonic transducers coupled to the object space wherein objects under examination are located or distributed; a second array of ultrasonic transducers coupled to a reconstitution space wherein the acoustic images of the objects are to be replicated; and time inversion means. The time inversion means has a set of waveform memories which first captures the ultrasonic signals from said objects, typically echos produced in response to suitable excitation, via said first array of ultrasonic transducers with suitable amplification and preconditioning as necessary. Then readouts of these signals are provided inversely in time which drive the second array of ultrasonic transducers with said time inverted signals to reproject inversely propagating ultrasonic wavetrains forming replicated acoustic images of the objects. By optically monitoring the ultrasonic energy distribution in said reconstitution space, via an opto-acoustic interaction effect, the system enables the observation of the object images in real time on each complete acquisition of said ultrasonic signal set at the first array of transducers, i.e. one complete picture per each echo sounding, which means in case of a medical diagnostic system of up to several thousand pictures per second.