When color Doppler is active, how many pulses per scan line are typically used to create the underlying B-mode image?

When color Doppler is active, how many pulses per scan line are typically used to create the underlying B-mode image?

• A. 3-4
• B. 1-2
• C. 5-6
• D. 7-8

Answer: (B)

When color Doppler is active, the system must time-share each scan line between Doppler sampling and producing the structural B-mode brightness image. To keep the overall frame rate practical while still obtaining Doppler velocity information, the B-mode component is generated with only a small number of pulses per scan line—typically one or two. Using more pulses would slow the acquisition and reduce temporal resolution, making the color overlay and anatomy updates less fluid. So, the typical value is 1-2 pulses per scan line. Higher numbers would slow things down without providing enough additional B-mode benefit in this context.

When color Doppler is active, the system must time-share each scan line between Doppler sampling and producing the structural B-mode brightness image. To keep the overall frame rate practical while still obtaining Doppler velocity information, the B-mode component is generated with only a small number of pulses per scan line—typically one or two. Using more pulses would slow the acquisition and reduce temporal resolution, making the color overlay and anatomy updates less fluid. So, the typical value is 1-2 pulses per scan line. Higher numbers would slow things down without providing enough additional B-mode benefit in this context.