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Rib notching refers to an abnormal indentation or scalloping of the margins of the ribs, best seen on chest radiographs or CT.
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Inferior Rib Notching (Most Common)
Usually involves the inferior margins of the posterior ribs.
Mnemonic: "CANT"
| Domain | Features |
|---|---|
| CVS | • Coarctation of the aorta (most classic) → Enlarged collateral intercostal arteries erode the inferior rib margins. |
| • Blalock–Taussig shunt (postoperative) | |
| • Arteriovenous malformations (AVMs) | |
| • Pulmonary arteriovenous fistula | |
| • Superior vena cava (SVC) obstruction → Collaterals via intercostals. | |
| CNS | • Neurofibromatosis type 1 → Intercostal neurofibromas enlarge the intercostal nerves. |
| • Intercostal neuromas → Post-thoracotomy or trauma. | |
| MSK | • Hyperparathyroidism → Subperiosteal bone resorption. |
| • Thalassemia major → Marrow expansion causes bone changes. |
Other types: Uncommon
| Type | Pathologies |
|---|---|
| Superior Rib Notching | • ‣ ****→ Muscle atrophy leads to altered rib shape. |
| • Congenital absence of pectoralis major (‣) | |
| • Muscle atrophy (trauma, paralysis, surgery) | |
| Both Superior & Inferior Rib Notching | • Sickle cell anemia → Marrow hyperplasia + vascular changes. |
| • Mediastinal masses with intercostal vessel involvement |