What can you improve by changing gray-scale map?

• A. Axial resolution
• B. Lateral resolution
• C. Contrast resolution
• D. Temporal resolution

Answer: (C)

Changing the grayscale map affects how echo strengths are displayed as brightness on the image. The grayscale map is a lookup table that assigns a shade of gray to each echo amplitude, so adjusting it changes how differences in brightness are represented. This directly impacts contrast resolution—the ability to distinguish tissues with small differences in echogenicity. It doesn’t alter the physical properties that determine resolution along or across the beam (axial and lateral resolution) or the speed at which frames are acquired (temporal resolution). Those depend on pulse length, beam geometry, and frame rate, not on how the image is mapped to grayscale. So using a different grayscale map helps reveal subtle contrasts by improving contrast resolution.