Inferior Rib notching is seen in all except?

Answer is D (Neurofibromatosis) Neurofibromatosis is associated with superior rib notching Inferior rib notching is characteristically seen in coarctation of Aoa and may also be seen in Superior vena cava obstruction and a Blalock-Taussig shunt operation Rib-Signs in Coarctation of aoa: Inferior rib notching is characteristic, and is believed to be due to pressure erosion by intercostal aeries. Inferior rib notching takes several years to develop and is rarely seen before the age of 8 years.e '3' signemay be seen due to enlargement of left subclan aery above the coarctation Usually spares fist two ribse where intercostal aeries arise from costocervical trunk which is proximal to the usual site of CA. Mostly commonly affected ribs are the 4th to 8th ribs. Usually bilateral but asymmetrical.