What radiographic findings are generally associated with mild pulmonary venous hypertension? (PCWP = 15-20 mm Hg)

The pulmonary vascular diameter is equal in the upper and lower lobes. (Normally the upper-lobe vessels are smaller than the lower-lobe vessels, but they dilate with venous overload.)
The vessels in the first interspace should not exceed 3 mm in diameter. (Compare the upper lobe veins with the lower lobe veins equidistant from the hilum.)