Bilateral rib notching is seen in -

The differentials differ according to whether it is the superior or inferior surface that is notched. Superior rib notching * abnormal osteoblastic activity o osteogenesis imperfecta o connective tissue diseases SS rheumatoid ahritis SS systemic lupus erythematosus (SLE) SS Marfan syndrome SS Sjogren's syndrome SS scleroderma o local pressure * abnormal osteoclastic activity o hyperparathyroidism * miscellaneous o neurofibromatosis type 1 o restrictive lung disease o poliomyelitis o progeria o abnormal muscle pull Inferior rib notching (Roesler sign) * enlarged collateral vessels o coarctation of the aoa o interrupted aoic arch o subclan aery obstruction SS Takayasu disease SS Blalock-Taussig shunt: involves only upper two rib spaces o aeriovenous malformation (AVM) of the chest wall o superior vena cava obstruction with enlarged venous collaterals o pulmonary AVM o tetralogy of Fallot * neurogenic tumors o schwannoma (usually single) o neurofibromatosis type 1 (rarely can be superior if neurofibroma is very large) Superior and inferior rib notching * hyperparathyroidism * neurofibromatosis type 1