In M-mode displays, which arrangement best describes the axes?

In M-mode displays, which arrangement best describes the axes?

• A. Time on the horizontal axis; depth on the vertical axis
• B. Depth on the horizontal axis; time on the vertical axis
• C. Time on both axes
• D. Depth on both axes

Answer: (A)

M-mode displays capture motion along a single ultrasound line over time. The horizontal axis represents time, moving left to right so you can watch how the same line of tissue changes as time progresses. The vertical axis represents depth, measured from the transducer into the body, showing how far the reflecting point is from the probe. This setup creates a depth-versus-time trace, letting you see motion toward or away from the transducer as it unfolds in time. If depth were placed on the horizontal axis or time appeared on both axes, you’d lose a clear view of how depth changes over time, making it hard to interpret movement. So the standard arrangement is time on the horizontal axis and depth on the vertical axis.

M-mode displays capture motion along a single ultrasound line over time. The horizontal axis represents time, moving left to right so you can watch how the same line of tissue changes as time progresses. The vertical axis represents depth, measured from the transducer into the body, showing how far the reflecting point is from the probe. This setup creates a depth-versus-time trace, letting you see motion toward or away from the transducer as it unfolds in time. If depth were placed on the horizontal axis or time appeared on both axes, you’d lose a clear view of how depth changes over time, making it hard to interpret movement. So the standard arrangement is time on the horizontal axis and depth on the vertical axis.