A result of photoelectric absorption is increased:

• A. Distortion
• B. Receptor Exposure
• C. Spatial Resolution
• D. Image Contrast

Answer: (D)

Photoelectric absorption is the process where an X-ray photon is fully absorbed by an atom, ejecting an inner-shell electron. This interaction is more probable at lower photon energies and with higher atomic-number materials. In the body, bone (high Z) absorbs more photons photoelectrically than soft tissue, so the beam is attenuated more through bone than through surrounding tissue. This increases the difference in transmitted intensity between structures, which shows up as greater image contrast on the radiograph. Receptor exposure would actually decrease as more photons are absorbed, and spatial resolution or distortion aren’t directly raised by this absorption effect. So the result of photoelectric absorption is increased image contrast.