"Acoustic shadowing (sometimes referred to as posterior acoustic shadowing) is a form of ultrasound artifact. It is characterised by the apparent lack of signal deep to an imaged tissue interface, due to all (or nearly all) of the transmitted sound wave being reflected back to the transducer or absorbed by the tissue. It commonly occurs when an area of interest contains a high Z/solid tissue (e.g. calcified gallstone or bone) or at an interface with high acoustic impedance mismatch (e.g. soft tissue/air)."
"Acoustic shadowing (sometimes referred to as posterior acoustic shadowing) is a form of ultrasound artifact. It is characterised by the apparent lack of signal deep to an imaged tissue interface, due to all (or nearly all) of the transmitted sound wave being reflected back to the transducer or absorbed by the tissue. It commonly occurs when an area of interest contains a high Z/solid tissue (e.g. calcified gallstone or bone) or at an interface with high acoustic impedance mismatch (e.g. soft tissue/air)."
"The intensity of the shadow can be manipulated by adjusting the depth of focus; the closer the depth of focus is to the object creating the shadow, the greater the shadow will be 2."