What is the primary effect of increasing transmit power on image quality?

What is the primary effect of increasing transmit power on image quality?

• A. Decreases frame rate
• B. Increases signal-to-noise ratio
• C. Worsens axial resolution
• D. Decreases penetration

Answer: (B)

Increasing transmit power makes the emitted ultrasound pulse stronger, so the echoes that return have greater amplitude. The system’s noise level stays roughly the same, so the signal-to-noise ratio improves. A higher SNR means interfaces between tissues are more detectable, speckle becomes less pronounced, and the overall image appears crisper with better contrast. Frame rate, axial resolution, and penetration aren’t directly controlled by transmit power. Frame rate depends on pulse repetition frequency and imaging depth; axial resolution is set by the pulse length and wavelength; penetration is mainly influenced by tissue attenuation and frequency. Keep in mind that higher power increases patient exposure, so it must be used within safety limits.

Increasing transmit power makes the emitted ultrasound pulse stronger, so the echoes that return have greater amplitude. The system’s noise level stays roughly the same, so the signal-to-noise ratio improves. A higher SNR means interfaces between tissues are more detectable, speckle becomes less pronounced, and the overall image appears crisper with better contrast.

Frame rate, axial resolution, and penetration aren’t directly controlled by transmit power. Frame rate depends on pulse repetition frequency and imaging depth; axial resolution is set by the pulse length and wavelength; penetration is mainly influenced by tissue attenuation and frequency. Keep in mind that higher power increases patient exposure, so it must be used within safety limits.