Which of the following can be affected by coherent interactions that occur during a radiographic procedure?

• A. patient dose
• B. occupational dose
• C. image quality
• D. absorbed dose

Answer: (C)

Coherent interactions are elastic, meaning the photon changes direction but keeps almost all its energy and does not transfer energy to the tissue. Since there’s no energy deposited in that interaction, coherent scattering doesn’t contribute to absorbed dose at the location of the interaction. The key effect in radiography is at the image receptor: those scattered photons that reach the detector add background fog and blur, reducing image contrast and overall image quality. The other choices involve dose, which is governed by energy deposited through different interactions (photoelectric and Compton), not by coherent scattering. So the aspect actually affected by coherent scattering is image quality.