A chest radiograph shows inferior rib notching along the undersurface of ribs 3 to 8 with a normal appearance of the first two ribs. Which congenital cardiovascular lesion is the most likely diagnosis?
- A Patent ductus arteriosus
- B Postductal coarctation of the aorta ✓
- C Tetralogy of Fallot
- D Total anomalous pulmonary venous connection
Correct answer: B. Postductal coarctation of the aorta
Explanation
In postductal (adult-type) coarctation, collateral flow via dilated intercostal arteries erodes the inferior rib margins, producing notching of ribs 3 to 8. Ribs 1 and 2 are spared because their intercostal arteries arise proximal to the coarctation from the costocervical trunk. This sparing is the fact that kills distractors like patent ductus arteriosus, which causes no rib notching at all.
Reference: Grainger and Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.