Ascending aortic dilatation seen as a bulge along the right upper cardiac border, above the right atrial contour. Dilatation of ascending aorta can be part of annuloaortic ectasia with associated aortic regurgitation. Post stenotic dilatation of aorta in valvar aortic stenosis also occurs like this. In valvar aortic stenosis, the eddy currents caused by the jet across the stenotic valve is thought to cause the post stenotic dilatation of aorta. There is no direct correlation between the severity of post stenotic dilatation and the severity of aortic stenosis. This is more so in case of pulmonary stenosis. Post stenotic dilatation is not seen in subvalvar stenosis. The x-ray also shows mild enlargement of the cardiac silhouette.