Inferior rib notching is present in -

Ans. is 'a>c' i.e., Coarctation of aorta > Fallot's tetralogy o Causes of rib notching ae : -A) Inferior surface1) Arteriali) Coarctation of aorta Bilateral Rib notching is seen on the lower border of 3rd to 8th ribs. Rib notching is absent in the 1st & 2nd ribs. Rib notching is usually present after the age of 7 years.ii) Aortic thrombosis (aortic obstruction) or aortitis.iii) Subclavian obstruction after Blalock operation for Fallot's tetralogy (Taussig Blalock operation).iv) Pulmonary oligemia Pulmonary atresia, TOF, absent pulmonary artery.2) Venous : - SVC obstruction3) Arteriovenous : - Pulmonary arteriovenous malformation, chest wall arteriovenous malformation.4) Neurogenic : - Neurofibromatosis.B) Superior surface1) Connective tissue diseases : - SLE, Scleroderma, RA, Sjogren's syndrome.2) Metabolic : - Hyperparathyroidism3) Miscellaneous : - Neurofibromatosis, Restrictive lung disease, Poliomyelitis, Marfan's syndrome, progeria, Osteogenesis imperfecta.