What is the primary difference between color Doppler imaging and spectral Doppler?

• A. Spectral provides velocity spectrum at a point.
• B. Color shows velocity over a region.
• C. Color provides a velocity spectrum at a point.
• D. Spectral shows velocity over a region.

Answer: (B)

Color Doppler imaging shows velocity over a region by overlaying color on the image to map flow across the scanned area, giving a spatial pattern of speed and direction throughout the field of view. Spectral Doppler, in contrast, samples a small location with a gate and outputs a velocity spectrum over time, providing exact velocity data at that single site. So the hallmark difference is region-wide velocity mapping versus a point-based velocity spectrum.