Which term is used for the process that transfers echo data into a format suitable for grayscale imaging?

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

Answer: (A)

The main concept is how echo data are converted into a display-ready format for grayscale imaging. The scan converter is responsible for taking the echoes gathered along the scan lines and mapping them into the rectangular grid of pixels that the monitor displays. It handles the spatial reformatting from the transducer’s geometry (often polar or sector scans) to the display’s coordinates, and it may perform interpolation so every screen pixel has a brightness value corresponding to the echo strength. This step is what makes the real-time grayscale image possible, turning raw data into a coherent picture.

Envelope refers to extracting the amplitude of the signal from the RF waveform, which happens earlier in the signal chain. Speckle is the grainy texture that arises from interference of many echoes. Rejection/thresholding suppresses low-amplitude echoes to reduce noise, but it doesn’t reorganize data for display.