Why is ultrasound the gold standard for screening for an abdominal aortic aneurysm (AAA)?

• A. Ultrasound can detect mural thrombi and sac diameter, while angiography only visualizes the patent lumen
• B. Angiography visualizes the entire aneurysm including mural thrombi
• C. Ultrasound exposes patients to harmful radiation
• D. Angiography is cheaper and more accessible than ultrasound

Answer: (C)