Diagnostic ultrasound ( PDFDrive )

APPENDIX Ultrasound Artifacts: A Virtual Chapter
e7
PATH OF SOUND-RELATED
ARTIFACTS
In mapping a returning echo onto the generated image, an
assumption is made that it originated from the same part of the
transducer from which it was produced. Also, an assumption is
made that the echo is the result of a single relection. he depth
of the relector is calculated based on the time it took for the
sound wave to travel from the transducer to the relector and
back, assuming a single relection. When these assumptions do
not hold, various types of artifacts occur.
Click here to see an explanatory video of path of sound
assumption (Video A.6).
Mirror Image Artifact
A mirror image artifact is created when the primary beam
encounters a highly relective surface that acts like a mirror. he
relected echoes then encounter other relectors and bounce back
onto the mirror before being directed to the transducer. he
result is artifactually inverted projection of the relectors deeper
to the surface of the mirror. he image is displayed deeper because
of the longer path of the relected sound. If the mirror image
artifact causes confusion, it can be decreased or eliminated by
moving the transducer to center it on the region of interest and/
or placing the focal zone at the level of interest in the real
structure.
Click here to see an explanatory video of mirror image artifact
(Video A.7).