Backscattering in OCT refers to light that is scattered back toward the light source/detector.

Backscattering in OCT refers to light that is scattered back toward the light source/detector.

• A. Forward scattering at small angles
• B. Backscattering: light deflected back toward the light source at 180 degrees
• C. Refraction at tissue interfaces
• D. Absorption of light

Answer: (B)

Backscattering is the portion of light that, after interacting with tissue, travels back toward the light source and detector. In OCT, this backward-directed light, often described as returning along roughly the opposite direction to the incident beam (around 180 degrees), is what interferes with light from the reference arm to form the depth-resolved image. Forward scattering sends photons deeper into the tissue and away from the detector, so it doesn’t contribute to the OCT signal. Refraction describes bending at interfaces due to refractive index changes, not necessarily returning light to the detector. Absorption removes photons without sending them back toward the detector. Therefore, light deflected back toward the light source at 180 degrees best characterizes backscattering in OCT.

Backscattering is the portion of light that, after interacting with tissue, travels back toward the light source and detector. In OCT, this backward-directed light, often described as returning along roughly the opposite direction to the incident beam (around 180 degrees), is what interferes with light from the reference arm to form the depth-resolved image. Forward scattering sends photons deeper into the tissue and away from the detector, so it doesn’t contribute to the OCT signal. Refraction describes bending at interfaces due to refractive index changes, not necessarily returning light to the detector. Absorption removes photons without sending them back toward the detector. Therefore, light deflected back toward the light source at 180 degrees best characterizes backscattering in OCT.