Color "bruit" artifact

Color bruit refers to the display of color superimposed over tissue adjacent to a hemodynamically significant stenosis due to the vibration of the tissue.

A hemodynamically significant stenosis causes turbulence.  Turbulence causes vibration in the tissue adjacent to the stenosis.   When this vibration can felt (palpated) by a doctor it is called a “thrill”.  When it can be heard by a doctor using a stethoscope it is called a "bruit".

Since the thrill is vibrating, moving tissue, these vibrations produce true Doppler shifts which the color Doppler system displays on the screen, superimposed on the moving tissue.  The result is the display of a mosaic of color immediately surrounding a high-grade stenosis.  

Sonographers should recognize this and know that a color "bruit" can be a useful clue to the fact that there is a high-grade stenosis in the immediate vicinity.     

A similar display can be seen with color Doppler in the presence of an arterial-venous fistula.

Revin et al have an excellent article in Radiographics on the topic of "Optimizing Image Quality When Evaluating Blood Flow at Doppler US: A Tutorial"  It has some excellent videos and I would highly recommend it.  Here is a link.