Diagnostic ultrasound ( PDFDrive )

APPENDIX Ultrasound Artifacts: A Virtual Chapter
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Reverberation Artifact
Reverberation artifact occurs when a strong relector runs
perpendicular to the direction of the beam (i.e., parallel to the
probe surface), usually close to the skin surface. 1 he sound
waves may then get partially “trapped” between the relector
and skin, reverberating back and forth and causing the appearance
of multiple regular lines when some of the waves eventually
reach the probe. Oten the relectors are the skin and subcutaneous
fascia (see Fig. A.31). Reverberation artifact is angle dependent,
so moving the transducer slightly will cause a decrease in or
elimination of the artifact. Reverberation can be helpful during
biopsies, to see a needle. If it is distracting, try changing the
angle of insonation, using a diferent window, or decreasing
the gain.
FIG. A.31 Reverberation Artifact. Reverberation artifacts arise when the ultrasound signal relects repeatedly between highly relective
interfaces near the transducer, resulting in delayed echo return to the transducer. This appears in the image as a series of regularly spaced echoes
at increasing depth. 2 (See Chapter 1, Fig. 1.27.)
FIG. A.32 Mirror Image and Reverberation Artifacts Behind a Pacemaker. The highly relective and mirrorlike surface of the pacemaker
(arrow) results in repeated bouncing of sound wave among the probe surface, pacemaker, and skin.