The cavitation threshold of human tissue exposed to 0.2-MHz pulsed ultrasound: Preliminary measurements based on a study of clinical lithotripsy

摘要: Abstract Evidence of acoustic cavitation was identified in the form transient echoes ultrasound B-scan images patients receiving extracorporeal shock-wave lithotripsy treatment on a Storz Modulith SL20. This lithotripter generates 10-μs duration pulses with centre frequency 0.2 MHz at pulse repetition 1 Hz. The visual appearance examined total 30 and quantitative analysis echogenicity changes carried out six cases involving stones renal pelvis. In these new were unaffected by movement artefacts found to occur perinephric fat adjacent muscle kidney tissue positions close axis field between 2 cm advance indicated beam focus lithotripter. within each region increased significantly above background level when output threshold value. pressures corresponding this measured water using calibrated PVDF membrane hydrophone. After correction for attenuation thresholds, terms temporal peak negative pressure, are lie 1.5 MPa 3.5 all cases. Interpretation values likely higher frequencies used diagnostic is considered theoretical model.