title: Lung damage from exposure to pulsed ultrasound.
abstract: Motivated by a recent finding that threshold pressures for hemorrhage in mouse lung exposed to the fields of an electrohydraulic lithotripter were less than 2 MPa, we extended the exposures to pulsed ultrasound. Sharply defined thresholds of the order of 1 MPa were found with 10 microseconds length pulses and roughly twice that value for 1 microsecond pulses. The thresholds at 4 MHz are greater than at 1 MHz. The thresholds are comparable for focused and unfocused fields. As would be expected for a cavitation-like phenomenon, temporal average intensity is a very poor predictor of this effect. In the extreme case, lesions were found at temporal average intensities on the order of 1 mW/cm2.
authors.affiliation: Department of Electrical Engineering, University of Rochester, NY 14627.
authors.forename: S Z
authors.initials: SZ
authors.lastname: Child
authors.forename: C L
authors.initials: CL
authors.lastname: Hartman
authors.forename: L A
authors.initials: LA
authors.lastname: Schery
authors.forename: E L
authors.initials: EL
authors.lastname: Carstensen
mesh_terms: D000818:Animals; D006470:Hemorrhage / Q000209:etiology*; D008171:Lung Diseases / Q000209:etiology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D014465:Ultrasonics / Q000009:adverse effects*