What does A-mode represent in ultrasound imaging?

A-mode, or Amplitude mode, is a form of ultrasound imaging primarily used to represent the amplitude of reflections received by the transducer. In A-mode imaging, the amplitude of the returning echo is displayed on the y-axis, while the depth of the structure from which the echo is reflected is represented on the x-axis. Each echo corresponds to a returning sound wave, which is plotted as a vertical line on the display; the height of this line indicates the strength or amplitude of the echo, reflecting how much of the ultrasound wave was reflected back from the tissue at that particular depth.

This method enables clinicians to visualize the amplitude of signals from different depths in the tissue, which is particularly useful in applications like assessing structures in the eye or guiding procedures such as biopsies where precise measurements of depth and amplitude are critical. In contrast, the other options touch on different aspects of ultrasound physics but do not accurately define what A-mode represents.