In the images in the previous question, what technique is used to fill in the empty data between the scan lines?

• A. Apodization
• B. Interpolation
• C. Dynamic receive
• D. Subdicing

Answer: (B)

The technique is interpolation. When ultrasound data are collected, there are gaps between the scan lines. Interpolation estimates values at those intermediate positions using the surrounding measured data, creating a smoother, denser image and improving lateral continuity. Simple methods like linear interpolation use a weighted average of neighboring lines, while more advanced approaches can use higher‑order mathematical fits for an even smoother result. Apodization shapes the transmit/receive aperture to reduce sidelobes, not to fill gaps between lines. Dynamic receive adjusts focus during reception, and subdicing is a hardware technique to subdivide elements to control grating lobes. So, filling in the empty data between scan lines is interpolation.