Tri-modality Cavitation Mapping in Shock Wave Lithotripsy

TL;DR

This paper introduces a tri-modality cavitation imaging system combining optical, active, and passive methods to accurately analyze cavitation dynamics in shock wave lithotripsy, enhancing understanding and potential clinical applications.

Contribution

The study develops and validates a novel integrated tri-modality cavitation imaging system that improves the accuracy and reliability of cavitation detection in SWL.

Findings

SW-PCM method shows high spatial-temporal accuracy

Tri-modality system effectively images cavitation in various conditions

Results support potential for in vivo applications in large animals and humans

Abstract

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.