Which control is used to compensate for signal loss with depth to keep brightness uniform?

Which control is used to compensate for signal loss with depth to keep brightness uniform?

• A. TGC
• B. Overall gain
• C. Output power
• D. Depth

Answer: (A)

Attenuation of ultrasound signals increases with depth, so to keep image brightness uniform you need depth-specific amplification. This is achieved with Time Gain Compensation (TGC), which applies more gain to echoes from deeper locations by using a depth-dependent amplification curve. That way, echoes from far tissue aren’t dimmed by attenuation as much, resulting in a consistently bright image across depths. The other controls don’t provide this targeted compensation: overall gain amplifies all echoes equally, so it can brighten near regions but won’t correct for depth-dependent loss; output power changes the transmitted intensity but doesn’t adjust the received signal’s brightness by depth; depth control simply sets how deep the image displays, not how the echoes are compensated.

Attenuation of ultrasound signals increases with depth, so to keep image brightness uniform you need depth-specific amplification. This is achieved with Time Gain Compensation (TGC), which applies more gain to echoes from deeper locations by using a depth-dependent amplification curve. That way, echoes from far tissue aren’t dimmed by attenuation as much, resulting in a consistently bright image across depths.

The other controls don’t provide this targeted compensation: overall gain amplifies all echoes equally, so it can brighten near regions but won’t correct for depth-dependent loss; output power changes the transmitted intensity but doesn’t adjust the received signal’s brightness by depth; depth control simply sets how deep the image displays, not how the echoes are compensated.