Mirror image artifacts occur when the transmitted pulse and returning echo reflect off of a highly reflective interface (an acoustic mirror) and change direction before returning to the transducer, thereby breaking this assumption.
The ultrasound machine makes a false assumption that the returning echo has been reflected once and hence the delayed echoes are judged as if being returned from a deeper structure, thus giving a mirror artifact on the other side of the reflective surface.
Study the first image to recognize the artefact. If you are sure about the location, swipe to the second image to view the answer (if applicable).
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