In B-mode, which axis represents depth?

In B-mode, which axis represents depth?

• A. Y axis
• B. X axis
• C. Time axis
• D. Depth axis

Answer: (A)

In B-mode imaging, depth is shown along the vertical axis of the image. As you move downward on the screen, you’re looking at tissue that is progressively deeper from the surface. The horizontal direction represents lateral position across the scan, and the brightness at each point encodes the strength of the echoes from that specific depth. This vertical mapping comes from the time it takes for the ultrasound pulse to return from different depths—the deeper the echo, the longer the return time, which is displayed lower on the screen.

In B-mode imaging, depth is shown along the vertical axis of the image. As you move downward on the screen, you’re looking at tissue that is progressively deeper from the surface. The horizontal direction represents lateral position across the scan, and the brightness at each point encodes the strength of the echoes from that specific depth. This vertical mapping comes from the time it takes for the ultrasound pulse to return from different depths—the deeper the echo, the longer the return time, which is displayed lower on the screen.