Learning objectives
To enlist the assumptions of the ultrasound beam
To depict the most commonly encountered artifacts
To explain the physical principles that lead to development of artifacts
Background
An artifact represents an acoustic image that does not correspond with the analyzed anatomical structure.
Ultrasound techniques are prone to plentiful artifacts,
which are commonplace in clinical practice and may induce confusion to the radiologist.
The main sources of artifacts are improper scanning technique and physical limits of the modality.
Some artifacts are undesired,
while others help to identify certain structures.
The key to understanding artifacts is the comprehension of ultrasound production,
propagation and interactions,
supported by a good knowledge of image generation.
Findings and procedure details
In order to determine the exact location and intensity of each echo and to produce an ultrasound image,
the equipment - despite its continuous development - still relies on the following basic physical assumptions:
1.
The pulse of ultrasound and its echo travel in a straight line.
2.
The resulted echo returns to the transducer after a single reflection.
3.
The time taken for an ultrasound to return to the transducer as an echo,
time of flight,
is directly related to the depth of an...
Conclusion
Despite the continuous improvement of the diagnostic method,
artifacts have not disappeared.
Their recognition is very important,
because some of them give clues regarding tissue composition and diagnosis,
while others may lead to misdiagnosis.
The ability to identify and eliminate potentially correctable ultrasound artifacts is important for enhancement of the scan quality and power of diagnosis,
therefore the best strategy of the physician is education and experience.
References
1) Feldman MK,
Katyal S,
Blackwood MS.
US artifacts.
Radiographics 2009;29:1179-1189.
2) McGahan JP,
Goldberg BB.
Diagnostic Ultrasound.
2nd Edition.
New York: Informa Healthcare; 2008.
3) Schmidt G.
Thieme Clinical Comparisons Utrasound.
3rd Edition.
Stuttgart.
Georg Thieme Verlag; 2007.
4) Hirsch MS,
Palavecino TB,
Leon BR.Color doppler twinkling artifact: A misunderstood anduseful sign.Revista Chilena de Radiología.
2011;17 (2): 82-84.
5) Graff D,
Ng M,
Rodriguez M.
Color Doppler ultrasound.https://wiki.engr.illinois.edu/display/BIOE414/Team+3+-+Color+Doppler+Ultrasound
