Coronary angiography is a medical imaging technique used to visualize the blood vessels of the heart. It involves injecting a special dye into the coronary arteries, which helps to highlight any blockages or narrowing in the vessels. This procedure is often performed in a hospital setting and is essential for diagnosing heart conditions. During the procedure, a thin tube called a catheter is inserted into a blood vessel, usually in the arm or groin, and guided to the heart. X-ray images are then taken to assess the flow of blood and identify any issues, allowing doctors to plan appropriate treatments.