What is the effect of increasing the dynamic range setting on the display of an ultrasound image?

What is the effect of increasing the dynamic range setting on the display of an ultrasound image?

• A. Increasing image brightness
• B. Decreasing image contrast
• C. Improving spatial resolution
• D. Increasing rejection of low-level echoes

Answer: (B)

Dynamic range is about how many gray shades the display can show for echo intensities. When you increase the dynamic range, more gray levels are used, so the difference between bright and dark echoes is spread over a wider range. That compression of brightness differences makes the image look more uniform, reducing overall contrast. So the display appears with less contrast as dynamic range goes up. Note that brightness is controlled by gain, and spatial resolution by frequency and imaging settings, not by dynamic range, and the rejection of low-level echoes is a different display/processing control.

Dynamic range is about how many gray shades the display can show for echo intensities. When you increase the dynamic range, more gray levels are used, so the difference between bright and dark echoes is spread over a wider range. That compression of brightness differences makes the image look more uniform, reducing overall contrast. So the display appears with less contrast as dynamic range goes up. Note that brightness is controlled by gain, and spatial resolution by frequency and imaging settings, not by dynamic range, and the rejection of low-level echoes is a different display/processing control.