During diagnostic coronary angiography, what is the purpose of contrast injections?

• A. Visualize the coronary arteries and assess stenoses
• B. Assess kidney function
• C. Measure blood glucose
• D. Evaluate liver function

Answer: (A)

The contrast injections are used to visualize the coronary arteries by opacifying the vessel lumen with iodine-containing contrast. This brightens the arteries on X-ray so you can clearly see their anatomy, identify any narrowing or blockages, and measure the severity of stenoses. The injections are timed and often performed from multiple angles to map the arteries and assess blood flow through the coronaries.

These injections aren’t used to assess kidney function, measure blood glucose, or evaluate liver function—those are determined by separate lab tests or imaging studies.