Artifacts in Sonography – Part 3

Abstract

As a continuation of parts 1 1 and 2 2, this article discusses artifacts as caused by insufficient temporal resolution, artifacts in color and spectral Doppler sonography, and information regarding artifacts in sonography with contrast agents. There are artifacts that occur in B-mode sonography as well as in Doppler imaging methods and sonography with contrast agents, such as slice thickness artifacts and bow artifacts, shadows, mirroring, and artifacts due to refraction that appear, for example, as double images, because they are based on the same formation mechanisms. In addition, there are artifacts specific to Doppler sonography, such as the twinkling artifact, and method-based motion artifacts, such as aliasing, the ureteric jet, and due to tissue vibration. The artifacts specific to contrast mode include echoes from usually highly reflective structures that are not contrast bubbles ("leakage"). Contrast agent can also change the transmitting signal so that even structures not containing contrast agent are echogenic ("pseudoenhancement"). While artifacts can cause problems regarding differential diagnosis, they can also be useful for determining the diagnosis. Therefore, effective use of sonography requires both profound knowledge and skilled interpretation of artifacts.

Contrast-Enhanced Ultrasound Improves the Accuracy of the ACR TI-RADS in the Diagnosis of Thyroid Nodules Located in the Isthmus

“…Artifacts in CEUS can cause problems regarding diagnosis. A "pseudoenhancement" artifact might occur in thyroid nodules with punctate echogenic foci (microcalcifications) on CEUS examination; it is produced by the nonlinear propagation of the US beam through contrast agent, so that punctate echogenic foci might be mistaken for microbubbles [27,28].…”

Artifacts in Musculoskeletal Ultrasonography: From Physics to Clinics

“…When the US beam travels through an area with strong impedance, the delayed return of the US signals to the transducer leads to overestimation of the depth of the object. In contrast, if the target is located in an area of low acoustic impedance, the object shown on the monitor appears shallower than it actually is ( Figure 12 A) [ 33 ].…”