ª Springer Science+Business Media New York 2015
Abdominal Imaging
Abdom Imaging (2015) DOI: 10.1007/s00261-015-0374-3
The color comet tail artifact ‘‘twinkle sign’’ Aurela Clark, Halemane Ganesh, David Di Santis Department of Radiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, USA
The twinkling or color comet tail artifact appears on Doppler ultrasound (US) scans as a rapidly shifting mixture of red and blue deep to a strongly reflective stationary structure, creating the false impression of movement [1]. It is most often observed when the acoustic beam encounters a rough surface with crevices. The greater the surface roughness, the greater the ‘‘twinkle’’ [2].
One theory attributes the artifact to splitting of the acoustic wave by the rough-surfaced reflector [1]. Another ascribes it to slight time fluctuations in transmitted and reflected waves, amplified by the irregular strongly reflective interface [3]. Because of its usefulness in detecting pathology, the ‘‘twinkle’’ has graduated from artifact to imaging sign. For example, occult renal calculi obscured by echogenic renal sinus
Fig. 1. Twinkle artifact in nephrolithiasis: sagittal images of the left kidney, both gray-scale (left) and color Doppler (right). An 8-mm echogenic focus with posterior acoustic shadowing
(blue arrow) is more conspicuous with Doppler imaging. The Twinkle artifact gives the stone a long, difficult-to-overlook flashing red and blue tail (red arrow).
Correspondence to: Aurela Clark; email: [email protected]
A. Clark et al.: The color comet tail artifact ‘‘twinkle sign’’
fat can be revealed by their telltale twinkle sign [4] (Fig. 1). In addition to urinary calculi, the twinkle sign has been reported with widely varying conditions including biliary calculi, encrusted urinary stents, gallbladder adenomyomatosis, and bile duct hamartomas [4].
References 1. Rahmouni A, Bargoin R, Herment A, Bargoin N, Vasile N (1996) Color Doppler twinkling artifact in hyperechoic regions. Radiology 199:269–271.
2. Tchelepi H, Ralls P (2009) Color comet-tail artifact: clinical applications. AJR Am J Roentgenol 192:11–18. 3. Kamaya A, Tuthill T, Rubin JM (2003) Twinkling artifact on color Doppler sonography: dependence on machine parameters and underlying cause. AJR Am J Roentgenol 180:215–222. 4. Turrin A, Minola P, Costa F, et al. (2007) Diagnostic value of color Doppler twinkling artifact in sites negative for stones on B mode renal sonography. Urol Res 35(6):313–317.
Abdominal Imaging
Abdom Imaging (2015) DOI: 10.1007/s00261-015-0374-3
The color comet tail artifact ‘‘twinkle sign’’ Aurela Clark, Halemane Ganesh, David Di Santis Department of Radiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, USA
The twinkling or color comet tail artifact appears on Doppler ultrasound (US) scans as a rapidly shifting mixture of red and blue deep to a strongly reflective stationary structure, creating the false impression of movement [1]. It is most often observed when the acoustic beam encounters a rough surface with crevices. The greater the surface roughness, the greater the ‘‘twinkle’’ [2].
One theory attributes the artifact to splitting of the acoustic wave by the rough-surfaced reflector [1]. Another ascribes it to slight time fluctuations in transmitted and reflected waves, amplified by the irregular strongly reflective interface [3]. Because of its usefulness in detecting pathology, the ‘‘twinkle’’ has graduated from artifact to imaging sign. For example, occult renal calculi obscured by echogenic renal sinus
Fig. 1. Twinkle artifact in nephrolithiasis: sagittal images of the left kidney, both gray-scale (left) and color Doppler (right). An 8-mm echogenic focus with posterior acoustic shadowing
(blue arrow) is more conspicuous with Doppler imaging. The Twinkle artifact gives the stone a long, difficult-to-overlook flashing red and blue tail (red arrow).
Correspondence to: Aurela Clark; email: [email protected]
A. Clark et al.: The color comet tail artifact ‘‘twinkle sign’’
fat can be revealed by their telltale twinkle sign [4] (Fig. 1). In addition to urinary calculi, the twinkle sign has been reported with widely varying conditions including biliary calculi, encrusted urinary stents, gallbladder adenomyomatosis, and bile duct hamartomas [4].
References 1. Rahmouni A, Bargoin R, Herment A, Bargoin N, Vasile N (1996) Color Doppler twinkling artifact in hyperechoic regions. Radiology 199:269–271.
2. Tchelepi H, Ralls P (2009) Color comet-tail artifact: clinical applications. AJR Am J Roentgenol 192:11–18. 3. Kamaya A, Tuthill T, Rubin JM (2003) Twinkling artifact on color Doppler sonography: dependence on machine parameters and underlying cause. AJR Am J Roentgenol 180:215–222. 4. Turrin A, Minola P, Costa F, et al. (2007) Diagnostic value of color Doppler twinkling artifact in sites negative for stones on B mode renal sonography. Urol Res 35(6):313–317.
