Which radiographic finding is classically associated with Tetralogy of Fallot?

Which radiographic finding is classically associated with Tetralogy of Fallot?

• A. Globular heart
• B. Egg-on-a-string
• C. Boot-shaped heart
• D. Normal heart

Answer: (C)

The main idea here is recognizing the classic radiographic sign of Tetralogy of Fallot. On a frontal chest radiograph, Tetralogy of Fallot typically produces a boot-shaped heart. This silhouette comes from marked right ventricular hypertrophy, which lifts and curves the apex upward, combined with relatively small pulmonary arteries due to outflow tract obstruction. The result is a curved, boot-like contour with reduced pulmonary markings from decreased blood flow to the lungs. Understanding this sign helps distinguish Tetralogy of Fallot from other conditions that can affect the heart’s silhouette. An egg-on-a-string appearance points to transposition of the great arteries rather than TOF, a globular heart can be seen in other processes that enlarge the cardiac silhouette, and a normal heart would not show the characteristic boot shape seen with TOF.

The main idea here is recognizing the classic radiographic sign of Tetralogy of Fallot. On a frontal chest radiograph, Tetralogy of Fallot typically produces a boot-shaped heart. This silhouette comes from marked right ventricular hypertrophy, which lifts and curves the apex upward, combined with relatively small pulmonary arteries due to outflow tract obstruction. The result is a curved, boot-like contour with reduced pulmonary markings from decreased blood flow to the lungs.

Understanding this sign helps distinguish Tetralogy of Fallot from other conditions that can affect the heart’s silhouette. An egg-on-a-string appearance points to transposition of the great arteries rather than TOF, a globular heart can be seen in other processes that enlarge the cardiac silhouette, and a normal heart would not show the characteristic boot shape seen with TOF.