Artefacts
Posterior enhancement
posterior enhancement refers to the increased echoes deep to structures that transmit sound very well. This is characteristic of fluid-filled structures (cysts, vessels, hyaluronic acid filler). The fluid only attenuates the sound less than the surrounding tissue. The time gain compensation overcompensates through the fluid-filled structure causing deeper tissues to be brighter. Simply it is seen as increased echogenicity (whiteness) posterior to thefluid filled structure.
Study the first image to recognize the different layers. If you are sure about the layers, swipe to the second image to view the answer (if applicable).