An Unusual Case of Mirror Image Artefact

ABSTRACT Mirror image artefact is a beam path artefact that occurs when the transmitted ultrasound beam and returning echo reflect off a highly reflective surface and change direction before returning to the transducer. This reflection alters the direction of the returning echoes. The ultrasound software interprets this as a duplicated structure across the reflective surface. Understanding the underlying mechanism of mirror image artefact is crucial to accurately recognise. This ensures that this artefact is not misinterpreted as true pathology, subsequently avoiding unnecessary further investigations and invasive procedures. The aim of this article is to present a rare illustration of mirror image artefact involving bone and discuss diagnostic techniques to help the reader differentiate this artefact from pathology.