The effect of polypropylene vials on lithotripter shock waves

Robin O. Cleveland, James A. McAteer, Sharon P. Andreoli, Lawrence A. Crum

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

In studies to understand the mechanisms responsible for shock wave lithotripsy (SWL) cell injury, we observed that shock waves (SWs) are influenced by the shape of the specimen vial. Lytic injury to kidney cells treated in a Dornier HM3 lithotripter was higher (p < 0.0001) when SWs entered the vial through the flat end (cap end) compared to the round end. Measurements of the acoustic field within polypropylene vials were carried out using both lithotripter SWs and pulsed ultrasound (US) in the megahertz frequency range. We compared pressure amplitudes inside the round and flat vials and found significant differences. When SWs entered through the round end, the average peak positive pressure was 40% of free-field pressure, due mostly to a dramatic reduction in pressure off axis. The average peak pressure inside the flat vial was twice that of the round vial. Experiments with US demonstrated that sound field focusing was induced by the curved interface of the round vial. Ray analysis for the round vial indicates the presence of 'hot spots' on axis and 'cold spots' off axis, in qualitative agreement with pressure profiles. We conclude that the shape of the specimen vial is an important factor that should be considered in model systems of SWL cell injury.

Original languageEnglish (US)
Pages (from-to)939-952
Number of pages14
JournalUltrasound in Medicine and Biology
Volume23
Issue number6
DOIs
StatePublished - Sep 1 1997

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Keywords

  • Cell injury
  • Polypropylene vials
  • Pressure measurements
  • Refraction
  • Shock wave lithotripsy
  • Ultrasound

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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