<prompt> Inferior rib notching is present inTAPVCCoarctation of aortaFallots tetralogyVentricular septal defect  <response>: Causes of rib notching ae: - A Inferior surface1 Arteriali Coarctation of aorta Bilateral Rib notching is seen on the lower border of 3 rd 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 Fallots tetralogy Taussig Blalock operation.iv Pulmonary oligemia Pulmonary atresia,1TOF, 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, Sjogrens syndrome.2 Metabolic : - Hyperparathyroidism3 Miscellaneous : - Neurofibromatosis, Restrictive lung disease, Poliomyelitis, Marfans syndrome, progeria, Osteogenesis imperfecta. 