What control should you adjust to better compensate for the attenuation of sound as it propagates through tissue?

• A. Dynamic range
• B. Time gain compensation
• C. Acoustic power output
• D. Rejection

Answer: (B)

Compensating for depth-related attenuation in ultrasound imaging. As sound travels through tissue, it loses energy and deeper echoes become weaker. To keep the image brightness consistent from near to far, the gain is adjusted as a function of depth so echoes from deeper regions get more amplification. This depth-dependent amplification is exactly what Time Gain Compensation provides: it boosts echoes more for greater depths (longer travel times) while leaving near echoes relatively unchanged, preserving overall image quality without increasing the emitted energy.

Dynamic range affects how wide the display’s brightness scale is, not how echoes are amplified by depth. Acoustic power output changes the overall energy of the pulses, which can improve penetration but also increases patient exposure and still doesn’t tailor amplification by depth. Rejection filters out low-amplitude signals to reduce noise, but it doesn’t compensate for attenuation with depth.