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Background, Motivation and Objective: Although it has been 10 years since microbubble contrast agents were first approved for clinical use, adoption has been slow,in spite of considerable technical advances and many successful clinical studies.Statement of Contribution/Methods: Methods for contrast specific imaging exploit the nonlinear response of bubbles at or near resonant excitation.Simple filtering for higher harmonics has given way to broadband methods using phase and/or amplitude modulation of a sequence of pulses.With suitable detection methods, linear, nonlinear,moving and stationary targets can all be segmented from the echo and shown in real time.The tendency of bubbles to disrupt at low peak negative pressures also offers a potential role for coded excitation on transmit.Deliberate disruption of bubbles with a few high MI pulses can clear the image plane and allow measurement of its replenishment by contrast offering a unique way to quantify microvaseular flow and perfusion volume.