SAFETY OF DIAGNOSTIC ULTRASOUND

Prof. Dr. Branko Breyer

Diagnostic ultrasound is widely used in modern medicine. Millions of ultrasound examinations are worldwide being performed per year. The scanned population includes everybody – from embryonic stage to late adulthood. This puts the methods and considerations of the safety of patients scanned with ultrasound into the field of radiation protection similar in principles to the much better known protection from ionizing radiation.

At the present stage the safety of diagnostic ultrasound is regulated in the USA by FDA regulations and rules. At the same time IEC committees 62B and 87 are in the course of creating safety recommendations in the field. At the present the document IEC 60601-2-37 is in an advanced stage of acceptance.

The general philosophy is the creation of labeling rules linked to various exposure parameters in such a way as to enable the operators to control the level of safety they operate at.

At the same time the regulations implicitly include exposure safety limits that stem from epidemiological research of exposure consequences during the last 30-35 years as well as animal and in-vitro biological experiments.

The general opinion is that given the known operating safety limits no adverse effects of the diagnostic ultrasound have been proven. However, known mechanisms like thermal mechanism, streaming and cavitation are known to exist and they necessitate further and continuing research and monitoring.

The guidelines have been implemented into Croatian law on the protection of non-ionizing radiation.