Which method reduces electronic noise in the ultrasound system?

Which method reduces electronic noise in the ultrasound system?

• A. Demodulation
• B. Compensation
• C. Rectification
• D. Rejection

Answer: (D)

Reducing electronic noise comes from a method that discards the faint, random signals that don’t represent real echoes. This approach, called rejection, acts like a noise gate: signals below a chosen threshold are ignored while stronger echoes pass through. By filtering out these low-amplitude components, the background noise and clutter diminish, making true tissue echoes stand out and improving the image’s signal-to-noise ratio. The other processes serve different roles—demodulation shifts the signal to a lower frequency for easier processing, rectification prepares the signal for envelope detection, and compensation adjusts for depth-related attenuation—so they don’t directly target noise the way rejection does.

Reducing electronic noise comes from a method that discards the faint, random signals that don’t represent real echoes. This approach, called rejection, acts like a noise gate: signals below a chosen threshold are ignored while stronger echoes pass through. By filtering out these low-amplitude components, the background noise and clutter diminish, making true tissue echoes stand out and improving the image’s signal-to-noise ratio. The other processes serve different roles—demodulation shifts the signal to a lower frequency for easier processing, rectification prepares the signal for envelope detection, and compensation adjusts for depth-related attenuation—so they don’t directly target noise the way rejection does.