Which test is considered the gold standard for diagnosing pulmonary embolism?

• A. Spiral CT
• B. Pulmonary Angiography
• C. V/Q Scan
• D. D-Dimer

Answer: (B)

Direct visualization of the clot in the pulmonary arteries is what makes pulmonary angiography the gold standard. By injecting contrast into the pulmonary artery and taking angiographic images, this test reveals a filling defect where a thrombus blocks blood flow, giving definitive confirmation of pulmonary embolism and precise information about the clot’s location and extent. While less invasive options like CT pulmonary angiography are now widely used first, and D-dimer and V/Q scans have important roles in screening or when CT isn’t possible, the definitive diagnostic standard is catheter-based pulmonary angiography.