Question

Radiological features of coarctation of aorta is/are -

• A. Reverse figure of 3 sign
• B. Rock sign
• C. Double aortic knuckle
• D. All of the above

Hint:

Think of the aortic contour, rib changes, and the reversed 3 outline together.

Answer 1

The Correct Option is D

Step 1: Coarctation of aorta (COA) is a narrowing of the aorta, classically at or near the site of the ligamentum arteriosum, just distal to the left subclavian artery. The narrowing alters blood flow and produces several characteristic plain-film signs.

Step 2: The reverse figure of 3 sign (also called the double bulge or E sign) is seen on a frontal chest radiograph. The upper bulge is the dilated aorta above the coarctation, the indentation is the coarctation itself, and the lower bulge is post-stenotic dilatation.

Step 3: The double aortic knuckle reflects the same two bulges of the aortic contour above and below the constriction. Rib notching (Dock's sign) results from enlarged collateral intercostal arteries eroding the inferior rib margins.

Step 4: Since all three features - reverse figure of 3 sign, the rib notching collateral sign, and the double aortic knuckle - are recognised radiological features of COA, the correct answer is All of the above.