Earliest feature of pulmonary venous hypeension is -
High-Yield Explanation
Upper lobe venous diversion is the 1st radiological sign of pulmonary venous hypeension.Kerley B Lines , perihilar haze ,peribronchial cuffing,pumonary ossicles ,fine punctuate calcification and perihilar batwing pattern are the other features seen in PVH.