A-scan yields what kind of data at a single lateral position?

A-scan yields what kind of data at a single lateral position?

• A. A two-dimensional depth map
• B. A one-dimensional depth profile of reflectivity
• C. A three-dimensional volume
• D. A color image

Answer: (B)

An A-scan provides a one-dimensional depth profile of reflectivity along the light path at a single fixed lateral position. It measures how the backscattered signal changes with depth, revealing peaks where there are interfaces between structures. Moving the beam laterally and collecting more A-scans builds a B-scan (a 2D cross-section), and stacking B-scans or scanning in two lateral directions forms a 3D volume. A color image is not the direct OCT data, though grayscale values may be displayed with color mapping. So, at one lateral position, you get a one-dimensional depth profile of reflectivity.

An A-scan provides a one-dimensional depth profile of reflectivity along the light path at a single fixed lateral position. It measures how the backscattered signal changes with depth, revealing peaks where there are interfaces between structures. Moving the beam laterally and collecting more A-scans builds a B-scan (a 2D cross-section), and stacking B-scans or scanning in two lateral directions forms a 3D volume. A color image is not the direct OCT data, though grayscale values may be displayed with color mapping. So, at one lateral position, you get a one-dimensional depth profile of reflectivity.