DIAGNOSTIC ULTRASOUND IN VETERINARY PRACTICE - HOW SAFE IS IT

This paper provides information on the safety of ultrasonic diagnostic procedures as currently used in veterinary practice. The known mechan isms of action are described and selected literature on biological eff ects of ultrasound is reviewed. Current international consensus is pre sented on the safety of medical ultrasound with respect to thermal eff ects. To date, there is no independently verified clinical evidence th at the level of exposure delivered to the tissues during scanned grey- scale ('B-mode') imaging has any adverse effects. Lung haemorrhage has been observed in animal experiments using diagnostic exposures, but t he effects have not been reported in the foetus. Equipment that uses p ulsed Doppler transmits higher acoustic outputs in a stationary beam, and can produce temperature increases that may have significant biolog ical consequences. When considering sonographic and pulsed Doppler exa minations of the prenatal animal, the safety margins are small and the operator should be aware of the acoustic output of the equipment, the exposure time, and the sensitivity of target tissues.