What is responsible for comet tail artifact?
In summary, comet tail artifacts are caused by an accumulation of cholesterol crystals in RASs and can be seen in cases of both chronic cholecystitis and xanthogranulomatous cholecystitis, as well as in cases of adenomyomatosis.
What do comet tails on ultrasound mean?
Comet-tails or “B-lines” are defined as hyperechoic reflections which originate only from and travel roughly perpendicular to the pleural line of the lung. They have a narrow base and form a ray spreading away from the transducer towards the bottom of the screen and synchronously move with lung respiration.
What is comet tail artifact in gallbladder?
The “comet tail” is a well-known ultrasound artifact that appears as a series of parallel bands radiating from a source. This artifact was ob- served in the gallbladder lumen in eight of 10 patients after extracor- poreal shock wave lithotripsy of ra- diolucent calculi.
What is the difference between comet tail and ring down artifact?
Comet-tail artifacts can be seen in normal and abnormal lungs and are described in more detail in Chapter 9 . Ring-down artifact is similar to comet-tail artifact but is produced by a different mechanism ( Figure 6.3 ). The source of ring-down artifact is a small pocket of fluid trapped by surrounding air bubbles.
What causes comet tail artifact in lung?
Comet tail artefact is a short path reverberation artefact that weakens with each reverberation, resulting in a vertical echogenic artefact that rapidly fades as it continues in to the ultrasound image. Normal lung. Sliding is seen as the two pleural surfaces move against each other through the respiratory cycle.
What causes gallbladder adenomyomatosis?
It occurs as a result of poorly understood hyperplastic changes involving the mucosa and muscular wall of the gallbladder and the formation of intramural sinuses, known as the Rokitansky-Aschoff sinuses, which are characteristic of this disease. Involvement of the gallbladder may be diffuse or segmental.
What causes comet-tail artifact in lung?
What will you do to lessen common artifacts in ultrasound?
Such artifacts most commonly occur when the needle is completely perpendicular to the US beam and can therefore be reduced by decreasing the angle of the US beam to <90°. In addition, a reduction in far gain will darken the distal artifacts.
What causes artifacts in ultrasound?
US artifacts arise secondary to errors inherent to the ultrasound beam characteristics, the presence of multiple echo paths, velocity errors, and attenuation errors.
Why are some artifacts considered useful in ultrasound imaging?
They can obscure deeper structures but can also be useful when detected in unexpected locations. Repetition artifacts are produced each time the sound wave pulse returns to the transducer after it hit a reflective surface (such as gas, bone or metal, particularly if this interface is near the transducer).
What is the pathophysiology of comet tail artifact in liver parenchyma?
B-mode sonogram showed multiple comet tail artifacts in the liver parenchyma, probably corresponding to the compact fibrosis bands and bile in the bile duct as well as peripheral bile duct dilatation, which was proven pathologically.
What is a comet tail artefact?
Comet tail artefact is a short path reverberation artefact that weakens with each reverberation, resulting in a vertical echogenic artefact that rapidly fades as it continues in to the ultrasound image. Normal lung. Sliding is seen as the two pleural surfaces move against each other through the respiratory cycle.
What does a comet tail look like on a B scan?
In the B-scans, a trail of dense continuous echoes, simulating a comet tail, is seen distal to each lead pellet. This comet tail appearance is shown to be a t … A description and explanation of an unexpected echographic appearance in a patient who had sustained an abdominal shotgun wound is presented.