Color-write priority

Color-write priority is an adjustable setting of color Doppler duplex ultrasound and determines whether a particular pixel on the image displays color or grayscale B-mode information at the moment.

Color-write priority is rarely changed directly during routine ultrasound imaging, even though it can significantly improve flow detection in low caliber vessels. While in large vessels there is a well-defined, mostly anechoic lumen easily written over with color information, the visible lumen of small vessels not only has a more discrete lumen, but it is also less likely to be anechoic due to e.g. reverberation artifacts. Adjusting the color-write priority (usually displayed as a horizontal bar on the grayscale spectrum) can facilitate the display of these vessels. This can be particularly useful e.g. in the interrogation of testicular blood flow . This also explains while less echogenic structures such as cysts are more likely to display color Doppler (flash) artifacts, as in the absence of significant B-mode signal the system will more easily overwrite the grayscale image with spurious color noise .