Which display mode is optimized for visualizing motion of internal structures over time?

• A. B-mode
• B. M-mode
• C. Cineloop
• D. A-mode

Answer: (B)

M-mode, or motion mode, is designed to show how structures move over time. It records along a single scan line and plots time on the horizontal axis while depth sits on the vertical axis, yielding a continuous trace of motion. This high temporal resolution makes it ideal for watching rapid, repetitive movements such as heart walls and valve movements, so you can see exactly how they change with each beat.

B-mode provides a 2D image of anatomy and isn’t focused on tracking motion along a line. Cineloop is a cine review of successive B-mode frames—great for playback but doesn’t inherently give you the line-by-line time–motion detail that M-mode provides. A-mode displays a single depth-amplitude trace and isn’t suited for visualizing motion over time in the way M-mode is.