Phase-change contrast agents (PCCAs) have advantageous properties in terms of smaller size, longer half-life and selective activation control compared to conventional microbubble contrast agents (MCAs), which make them ideal for ultrasound cancer imaging. [1] Acoustic signal from tumour site can be further enhanced by receptor targeted PCCAs. However there is still a lack of understanding of the behaviour of these targeted agents. In this work, we report the use of high frame rate (HFR) imaging to investigate the changes in acoustic signal of Folate Receptor (FR)-targeted versus control PCCAs with breast cancer cells immediately after acoustic activation.