A-mode

A-mode, or amplitude mode ultrasound, is a technique used to measure the distance to a specific point inside the body. It works by sending a short burst of sound waves into the tissue; when these waves hit a boundary between different tissues, they bounce back. The machine measures the time it takes for the echoes to return, and from this, calculates how deep the boundary is. A-mode produces a graph that displays the strength of the echoes as spikes along a line, helping doctors identify tissue layers or structures efficiently, often used in ophthalmology and other diagnostic fields.