Microbubble-based contrast imaging using phase shift systems and methods

Abstract

The present disclosure describes ultrasound systems configured to perform microbubble-based contrast imaging with enhanced sensitivity. The systems can enhance echo signals derived from microbubbles while suppressing echo signals derived from tissue by detecting phase shifts exhibited by microbubbles in resonance. To detect the phase shifts, and thereby distinguish between microbubble-based signals and tissue-based signals, the systems can transmit a series of ultrasound pulses into a target region in accordance with a predefined sequence. The sequence can include an initiation pulse configured to stimulate microbubbles into nonlinear oscillation, a detection pulse configured to detect the nonlinear oscillation, and a summation pulse formed by transmitting an initiation pulse and detection pulse with a small time delay therebetween. A signal processor included in the system can determine phase shifts exhibited by the signals generated in response to the series of pulses and mask non-microbubble-based signals based on the magnitude of the detected phase shifts.