TECHNIQUES FOR IMPROVING ULTRASOUND CONTRAST RATIO

摘要

An ultrasound technique exploits differences in statefulness of response in order to distinguish between the objects of interest. The method comprises transmitting a primary excitation signal and one or more secondary excitation signals; into a target medium receiving a corresponding plurality of responses from the target medium respectively resulting from the plurality of discrete excitation signals; and generating an output signal comprising the difference between the response to the primary excitation signal and either (i) the sum of the responses to the secondary excitation signals, or (ii) the sum of the response to a single secondary excitation signal and one or more time-shifted copies of the response to the single secondary excitation signal, the time shift being selected for appropriate alignment of the copy relative to the first response and the second response .