title: Ultrasound Artifacts - Part 2.
abstract: Part 2 discusses important artifacts in addition to those presented in part 1. Shadows and acoustic enhancement are based on regional differences in sound attenuation and are connected with the mode of action of depth gain compensation. They are not caused solely by the reflection properties of structures in terms of strong echoes → shadows, anechoic structure → acoustic enhancement. Anisotropy provides further evidence that echo strength is to be considered relative and is always linked to the equipment being used. Algorithms for "image improvement" can also result in artifacts as shown by black lines caused by image sharpening. Depending on the shape and position of the relevant structure, deviations from the assumed sound velocity result in incorrect positioning on the x-axis or refraction, which causes incorrect positioning on the y- and/or z-axis and may contribute significantly to shadows and acoustic enhancement.
authors.forename: Jörg A
authors.initials: JA
authors.lastname: Bönhof
mesh_terms: D000465:Algorithms; D016477:Artifacts; D004867:Equipment Design; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D056888:Patient Positioning / Q000379:methods; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods