  Shock wave lithotripsy (SWL) has been widely used for non-invasive treatment
of kidney stones. Cavitation plays an important role in stone fragmentation,
yet may also contribute to renal injury during SWL. It is therefore crucial to
determine the spatiotemporal distributions of cavitation activities to maximize
stone fragmentation while minimizing tissue injury. Traditional cavitation
detection methods include high-speed optical imaging, active cavitation mapping
(ACM), and passive cavitation mapping (PCM). While each of the three methods
provides unique information about the dynamics of the bubbles, PCM has most
practical applications in biological tissues. To image the dynamics of
cavitation bubble collapse, we previously developed a sliding-window PCM
(SW-PCM) method to identify each bubble collapse with high temporal and spatial
resolution. To further validate and optimize the SW-PCM method, in this work,
we have developed tri-modality cavitation imaging that includes 3D high-speed
optical imaging, ACM, and PCM seamlessly integrated in a single system. Using
the tri-modality system, we imaged and analyzed laser-induced single cavitation
bubbles in both free and constricted space and shockwave-induced cavitation
clusters. Collectively, our results have demonstrated the high reliability and
spatial-temporal accuracy of the SW-PCM approach, which paves the way for
future in vivo applications on large animals and humans in SWL.
