Shadowing


 * Reference for term: Musculoskeletal ultrasound - Holsbeeck Van, M. et al.
 * Technical definition: Artefact where the interfaces beyond a highly attenuating object appear lower in signal strength than adjacent interfaces with similar reflectivities.
 * Reference for definition: Ultrasound Physics and Instrumentation - Hedrick, W. et al.
 * Comment: Shadowing is seen at interfaces of materials that differ significantly in acoustic impedance. Classic examples of materials that produce shadowing are bone, air, calcifications.