Physics of ultrasound

Abstract

Procedures involving ultrasound have expanded into many areas of medicine, including anaesthesia. A good understanding of ultrasound and its benefits and limitations is therefore essential to anaesthetic prac-tice. This article outlines the fundamentals of ultrasound and how it is generated. Images obtained through ultrasound are often subject to artefact; the common artefacts encountered in clinical practice and dif-ficulties imaging certain tissues are explained. Various imaging modes including Doppler ultrasound and their uses are also described. Although largely a safe and widely used technique, the potential safety concerns and hazards resulting from the effects of ultrasound waves on body tissues are discussed.