Which density corresponds to the air within the oral-pharyngeal airway on imaging?

• A. Black
• B. Gray
• C. White
• D. Light gray

Answer: (A)

Air is radiolucent on imaging, meaning it attenuates X-rays very little and appears as a dark region. The oral-pharyngeal airway is filled with air, so on the image this area shows up as black. Soft tissues attenuate more and appear gray, while bone attenuates the most and appears white. Therefore, the density that matches air in the airway is black.