Which procedure is used to diagnose the severity of arterial blockages?

• A. Echocardiography
• B. MRI
• C. Stress test
• D. Cardiac catheterization

Answer: (D)

Determining how severe arterial blockages are is best done by directly visualizing the coronary arteries and measuring the impact on blood flow. Cardiac catheterization with coronary angiography accomplishes this: a catheter is threaded to the coronary arteries and contrast dye is injected while X-ray images are captured. This reveals the exact location and degree of narrowing and allows measurement of pressures and flow to assess whether a lesion is hemodynamically significant. In some cases, a physiology test like fractional flow reserve (FFR) is added during the procedure to determine if a narrowing truly limits blood flow and requires intervention.

Echocardiography looks at heart structure and function but does not image coronary artery blockages. MRI can image heart tissue and, in some protocols, vessels, but it isn’t the standard method for quantifying the severity of coronary stenosis. A stress test shows whether the heart develops ischemia under exertion, providing functional information, but it does not directly visualize or quantify the anatomical severity of blockages.