How does skin pigmentation affect exposure factors?

• A. 50% more exposure
• B. 100% more exposure
• C. no change in exp factors
• D. need less exposure

Answer: (C)

No change in exposure factors is expected from skin color. In diagnostic radiography, the amount of X-ray exposure needed to obtain a diagnostic image depends on how much the body part attenuates the beam, which is governed by tissue thickness and density (bone, muscle, fat) rather than the color of the skin. Melanin in the epidermis is a superficial pigment and absorbs X-rays only minimally at the energies used for imaging, so varying skin pigmentation does not meaningfully alter attenuation enough to require different kVp or mAs settings. Technique is adjusted for part thickness and composition, not pigmentation.