The measurement of lung water

Lung water can be measured by gravimetric determination, double indicator dilution technology, chest radiography, histology, thallium scintigraphy, nuclear magnetic resonance imaging, and positron emission tomography. Gravimetric determination is a reliable postmortem and research method. Double indicator dilution technology is an invasive technique which is reliable in some settings, but lacks correlation with gravimetric measurements in others. The chest radiograph is familiar and available, but is often insensitive to the early formation of edema, and radiographic changes often lag behind changes noted by other methods. Current histologic methods are not quantitative. Thallium scintigraphy has poor correlations with other methods. Nuclear magnetic resonance imaging and positron emission tomography are promising new techniques that require further investigation.