An ultrasonic imaging method including the following steps: a) transmitting ultrasonic energy to a subject under examination, said ultrasonic energy being generated by a plurality of electroacoustic transducers (110,110') which are actuated for transmission with predetermined delays according to a predetermined ultrasonic energy focusing rule; b) receiving the ultrasonic energy reflected by the subject under examination by means of an array of electroacoustic transducers (110,110'), the receiving transducers being actuated, the received signals detected thereby being read with predetermined delays according to a received signal focusing rule; c) turning the focused received signals into image data adapted to reconstruct the transmitted energy reflection points, which generated the energy reflected and detected by the electroacoustic transducers as a displayable image; d) actuating the transmitting transducers (110,110') with such delays as to generate a homogeneous acoustic field over all or at least a portion of the region of the subject under examination, which may be covered by the geometry of the whole array of transducers; e) transmitting the ultrasonic energy by two subgroups of transmitting electroacoustic transducers, the transducers of a first subgroup being actuated for transmission of ultrasonic energy with a predetermined waveform, and the transducers of the second subgroup being actuated for transmission of ultrasonic energy with a waveform that is the inverse of the predetermined waveform and that is shifted by a half-period out of phase, characterized in that f1) the transmitting transducers are actuated with such delays as to generate a fully defocused transmit beam or f2) to generate a limited defocused transmit beam g) while the received beam are focused upon reception to reconstruct the image to be displayed; k) the received signal of each transducer is sampled by analog-to-digital conversion and stored in a memory by using, as a storage address, the subject penetration depth, i.e. the instant or interval in which the corresponding part of the signal is received minus the delay that is imparted to the corresponding transducer to focus said part of the signal on one or more predetermined points, on one or more predetermined lines or on a predetermined region of the subject under examination. a) transmitting ultrasonic energy to a subject under examination, said ultrasonic energy being generated by a plurality of electroacoustic transducers (110,110') which are actuated for transmission with predetermined delays according to a predetermined ultrasonic energy focusing rule; b) receiving the ultrasonic energy reflected by the subject under examination by means of an array of electroacoustic transducers (110,110'), the receiving transducers being actuated, the received signals detected thereby being read with predetermined delays according to a received signal focusing rule; c) turning the focused received signals into image data adapted to reconstruct the transmitted energy reflection points, which generated the energy reflected and detected by the electroacoustic transducers as a displayable image; d) actuating the transmitting transducers (110,110') with such delays as to generate a homogeneous acoustic field over all or at least a portion of the region of the subject under examination, which may be covered by the geometry of the whole array of transducers; e) transmitting the ultrasonic energy by two subgroups of transmitting electroacoustic transducers, the transducers of a first subgroup being actuated for transmission of ultrasonic energy with a predetermined waveform, and the transducers of the second subgroup being actuated for transmission of ultrasonic energy with a waveform that is the inverse of the predetermined waveform and that is shifted by a half-period out of phase, f1) the transmitting transducers are actuated with such delays as to generate a fully defocused transmit beam or f2) to generate a limited defocused transmit beam g) while the received beam are focused upon reception to reconstruct the image to be displayed; k) the received signal of each transducer is sampled by analog-to-digital conversion and stored in a memory by using, as a storage address, the subject penetration depth, i.e. the instant or interval in which the corresponding part of the signal is received minus the delay that is imparted to the corresponding transducer to focus said part of the signal on one or more predetermined points, on one or more predetermined lines or on a predetermined region of the subject under examination.