Absolute lung density in experimental canine pulmonary edema.

The noninvasive quantification of pulmonary edema could be of importance in patient management. We have developed a portable Compton-scatter densitometer capable of measuring density in the range of 0.1-1 g/cm3 independently of the chest wall. Change in lung density was investigated in 19 dogs with pulmonary edema induced by a combination of raised left atrial pressure and hemodilution. The increase in lung density correlated with the postmortem assessment of lung water (r = 0.862, p less than 0.01) and with hemodynamic indicators of pulmonary edema (r = 0.749, p less than 0.01). Subtracting the intravascular component of lung density did not improve the correlation with postmortem lung water (r = 0.850, p less than 0.01). The measurement of absolute lung density by a Compton-scatter technique may be a potentially useful method of quantifying pulmonary edema.