Objective radiographic criteria to differentiate cardiac, renal, and injury lung edema

To assess the value of the chest radiograph in differentiating various types of pulmonary edema, we retrospectively analyzed 119 films of patients with pulmonary edema caused by left heart decompensation (group 1;N = 56), renal failure (group 2; N = 19), and lung microvascular injury (group 3; N = 44). Chest radiographs were examined independently by two trained observers, unaware of the clinical diagnosis, according to a standardized reading table. The two observers assigned chest films to the corresponding group with an accuracy of 86% and 90%, respectively. To test the observers' objectivity, we used radiographic findings as input variables for discriminant analysis. Computer-generated numerical functions identified pulmonary edema etiology with an accuracy of 88% when considering the three groups together. When groups were compared as pairs, percentages of correct classification were 91% (group 1 vs. group 2), 93% (group 1 vs. group 3), and 100% (group 2 vs. group 3). Thus, a standardized reading of chest radiographs may be considered a reliable clinical method for identifying pulmonary edema etiology.