Which term refers to leveling out the rough edges of signals to form a smoother waveform?

Which term refers to leveling out the rough edges of signals to form a smoother waveform?

• A. Rectification
• B. Envelope
• C. Rejection/Threshold/Suppression
• D. Speckle

Answer: (B)

The term describes forming the envelope. In ultrasound, the raw RF signal is a high-frequency carrier whose amplitude fluctuates with tissue echoes. To display a smooth waveform, the signal is rectified and then low-pass filtered to remove the rapid carrier, leaving a slowly varying curve that outlines the peaks—the envelope. This envelope represents reflection strength at each depth and is what becomes the brightness in B-mode imaging. Rectification alone just makes all values positive but keeps the jagged carrier; rejection/threshold/suppression removes weak signals rather than smoothing; speckle is the granular texture from interference and isn’t the smoothing process. So the smooth amplitude curve you’re after is the envelope.

The term describes forming the envelope. In ultrasound, the raw RF signal is a high-frequency carrier whose amplitude fluctuates with tissue echoes. To display a smooth waveform, the signal is rectified and then low-pass filtered to remove the rapid carrier, leaving a slowly varying curve that outlines the peaks—the envelope. This envelope represents reflection strength at each depth and is what becomes the brightness in B-mode imaging. Rectification alone just makes all values positive but keeps the jagged carrier; rejection/threshold/suppression removes weak signals rather than smoothing; speckle is the granular texture from interference and isn’t the smoothing process. So the smooth amplitude curve you’re after is the envelope.