Question 2834
{"accessible":false,"alternatives":[{"id":13829,"text":"ambiguity artifact"},{"id":13830,"text":"comet tail artifact"},{"id":13831,"text":"edge shadowing artifact"},{"id":13832,"text":"mirror artifact"},{"id":13833,"text":"speed error artifact"}],"archived":false,"correctAlternativeId":13831,"explanation":"\u003cp\u003eEdge shadowing occurs when an incident ultrasound pulse interact with the curved edges of a structure within tissue. The non-perpendicular interaction and change in speed from one tissue to another results in refraction. In refraction the transmittance angle does not equal the incidence angle. This results in a sliver of tissue extending posterior to the object's flanks that does not have transmitted ultrasound passing through, and therefore, no echoes are created in this region. This wedge of anechoic tissue is known as edge shadowing.\u003c/p\u003e\u003cp\u003eComet tail and mirroring occur due to reflection/reverberation. Speed error artifacts occur when sound travels through tissue with speeds that differ from the estimated soft tissue average. Ambiguity artifact occurs when an object deep to the field of view is registered within the specified field of view.\u003c/p\u003e","id":2834,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2834","nextQuestionPath":"/articles/speed-displacement-artifact-1/questions/2785","relatedArticles":[{"id":26561,"title":"Mirror image artifact","link":"/articles/mirror-image-artifact?lang=us"},{"id":31989,"title":"Reverberation artifact","link":"/articles/reverberation-artifact?lang=us"},{"id":46913,"title":"Refraction","link":"/articles/refraction?lang=us"},{"id":46914,"title":"Refraction artifact","link":"/articles/refraction-artifact-2?lang=us"},{"id":9930,"title":"Comet tail artifact","link":"/articles/comet-tail-artifact-4?lang=us"}],"alsoUsedIn":[{"id":1620,"kind":"RestrictedPage","title":"Page 1620 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/1620"},{"id":1984,"kind":"Course","title":"Imaging Physics: Ultrasound Peer Review - page 1984","link":"https://radiopaedia.org/courses/imaging-physics-ultrasound-peer-review/pages/1984"},{"id":1984,"kind":"Course","title":"Imaging Physics: Ultrasound - page 1984","link":"https://radiopaedia.org/courses/imaging-physics-ultrasound/pages/1984"}],"stem":"\u003cp\u003eWhich ultrasound artifact occurs as a result of refraction?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/2834"}],"attemptsPercentages":[{"alternativeId":"13833","percentage":5},{"alternativeId":"13831","percentage":63},{"alternativeId":"13832","percentage":14},{"alternativeId":"13829","percentage":5},{"alternativeId":"13830","percentage":13}],"promptToLogin":false,"questionManager":false,"articleId":"speed-displacement-artifact"}