The use of acoustic radiation force decorrelation weighted pulse inversion (ADW-PI) in enhancing microbubble contrast

Nonlinear echo signals from microbubbles are commonly isolated and visualized using techniques such as pulse inversion (PI) or contrast pulse sequences (CPS). Although these methods function by suppressing the linear signal component, they are still susceptible to detection of a false-positive nonlinear signal arising from strong tissue interfaces. In this study, acoustic radiation force (ARF) was added to a PI imaging sequence to induce motion of specifically-targeted microbubbles in a mouse hind limb tumor. The interframe signal decorrelation from this induced motion was then used to isolate microbubble signal based on its decorrelation characteristics. Results demonstrate that this technique of decorrelation filtering significantly improves microbubble contrast-to-tissue ratio (CTR) by 1.5 dB, and thereby allows for higher levels of specificity. ARF was shown to be effective in further enhancing performance.