Plain roentgenographic estimation of pulmonary vascular pressures: an improved technique: a catheter-correlated study of 215 patients with mitral valvular disease.

Our improvement on Turner's technique enabled more accurate plain x-ray estimation of pulmonary venous pressure (PVP) up to 60 mm and of systolic pulmonary arterial pressure (PAP) up to 150 mm in 215 patients catheterized for mitral valvular disease. Our improvement comprises (1) five main pulmonary artery (MPA) grades 0 to IV according to its area and volume; (2) modified pressure values assigned for MPA and kinetic energy of the right ventricle (required to pump blood into the pulmonary arterial bed) according to MPA grades; and (3) nine PVP grades from 0 to 8 with corresponding assigned PVP values. These modifications have enhanced the accuracy of the technique up to 85 to 95%.