Sister chromatid exchange and ultrasound.

Reported effects of ultrasound on sister chromatid exchange have been contradictory. These studies are discussed and their results, including ultrasonic dosimetry and biologic considerations, are compared. In the few studies showing positive effects, the magnitude was small, and the effects occurred as a result of in vitro exposure. Based on a review of these reports, there does not appear to be sufficient reason to alter presently held views on the safety of clinical ultrasound.