Bubble generation in excised canine urinary bladders using an electrohydraulic lithotripter

Microbubbles produced by cavitation in vivo could be used as ultrasound contrast agents without the need for injection. If produced in the bladder, microbubbles could be used to diagnose urinary tract diseases such as urinary reflux. In this study, the production of these bubbles was investigated. Urinary bladders were removed from dogs immediately after sacrifice with care taken to prevent the urine from draining or becoming contaminated. These bladders were exposed to a series of high-amplitude pulses from a Dornier HM-3 lithotripter. Small scatterers were produced by these fields which rapidly dissolved into the fluid when no other action was taken. These scatterers were identified as cavitation bubbles produced by the high-amplitude field. A continuous, standing field was used to try to prevent the dissolution of the bubbles through rectified diffusion