Possibility of Microcavitation from Diagnostic Ultrasound

Abstract

Abstmct-There is little or no definitive data in the literature that addresses the question of the possibility of adverse bioeffects in a single biological cell due to diagnostic ultrasound. A formula is derived that predicts the conditions that will produce transient acoustic cavitation on the scale of a single biological cell in one acoustic cycle. It is found that if the viscosity of the cellular medium or its surroundings is sufficiently low (within a factor of two or three of water, as with plasma) and if the frequency is sufficiently low (below 2-3 MHz), then some current diagnostic units may produce microcavitation when a small cavitation nuclei exists in or near a cell.