Positive contrast media are typically colored what on imaging?

Positive contrast media are typically colored what on imaging?

• A. Gray
• B. Black
• C. White
• D. Red

Answer: (A)

Positive contrast media are radiopaque substances used to opacify blood vessels or hollow structures. Because they strongly attenuate X-rays, they appear as bright, high-attenuation areas on imaging. In standard radiographs and angiograms, the highest attenuation maps to white, so positive contrast shows up as white against the gray background of tissues. Negative contrast media (like air) are much less attenuating and appear dark or black. The typical appearance of positive contrast is white, not gray.

Positive contrast media are radiopaque substances used to opacify blood vessels or hollow structures. Because they strongly attenuate X-rays, they appear as bright, high-attenuation areas on imaging. In standard radiographs and angiograms, the highest attenuation maps to white, so positive contrast shows up as white against the gray background of tissues. Negative contrast media (like air) are much less attenuating and appear dark or black. The typical appearance of positive contrast is white, not gray.