Cardiac imaging: the biological effects of diagnostic cardiac ultrasound

Diagnostic cardiac ultrasounds are an environment-friendly and non-ionising imaging technology. However, ultrasounds are not biologically inert, and their use might have profound clinical impact. This paper summarizes the known effects of cardiac ultrasound--compared to other major imaging techniques--to exposed patients and to clinically exposed physicians practising ultrasound imaging. Furthermore, this review also provides an overview of the evidences on the biological effects of diagnostic ultrasound--which suggest that ultrasound with frequency, intensity and duration fully in the diagnostic range have significant molecular, cellular and organ effects. A better understanding of these effects may improve our understanding of the complex interactions between ultrasound and biological tissues and may open new avenues to therapeutic applications based on the ultrasound-modulated cell functions, such as membrane transduction, apoptosis, cell permeability and thrombolysis.