A medical imaging system is proposed. The system includes means for providing a plurality of echo signals indicative of a response of a body part to a plurality of ultrasound pulsed waves having different acoustic pressures, the body part including a tissue being perfused with a contrast agent, and means for discriminating in the echo signals a contribution of a first type of contrast agent from a contribution of a second type of contrast agent and/or of the tissue, at least one harmonic component of the contribution of the first type of contrast agent having an acoustic power changing according to a first dependency law on the acoustic pressure and the at least one harmonic component of the contribution of the second type of contrast agent and/or of the tissue having an acoustic power changing according to at least one second dependency law on the acoustic pressure, wherein the means for discriminating includes means for significantly reducing the at least one harmonic component of the contribution of the second type of contrast agent and/or of the tissue with respect to the at least one harmonic component of the contribution of the first type of contrast agent according to the corresponding dependency laws.