Assessment of lung water content by roentgen videodensitometry

In 17 anesthetized and mechanically ventilated pigs, different degrees of lung injury were induced by iv infusion of oleic acid (mean dose 0.1 ml/kg). The change in radiologic density of the chest was measured by a videodensitometer before and 4 h after oleic acid infusion. The lungs were then removed for determination of the wet/dry weight ratio (WW/DW). The change in radiologic density was significantly correlated to WW/DW (r = .87) and to the changes in end-inspiratory pressure (r = .80), mean pulmonary arterial pressure (r = .77) and venous admixture (r = .79), but not to changes in the oncotic-hydrostatic pressure gradient of the lungs (r = .46). Roentgen videodensitometry appears to be a useful method for assessing changes in extravascular lung water content.