DISTINGUISHING HANTAVIRUS PULMONARY SYNDROME FROM ACUTE RESPIRATORY-DISTRESS SYNDROME BY CHEST RADIOGRAPHY - ARE THERE DIFFERENT RADIOGRAPHIC MANIFESTATIONS OF INCREASED ALVEOLAR PERMEABILITY

Hantavirus infection may cause diffuse air space disease, termed hanta virus pulmonary syndrome (HPS). The authors sought to determine if che st radiographs could differentiate HPS from typical acute respiratory distress syndrome (ARDS). The authors identified patients with either HPS (n = 11) or acute ARDS (n = 32) and selected the earliest chest ra diograph showing diffuse airspace disease, and a chest radiograph take n 24 to 45 hours previously. Thoracic and general radiologists first v iewed the chest radiograph showing diffuse air space disease, and rank ed the likelihood that each case represented HPS versus ARDS. Afterwar d, readers viewed earlier chest radiographs and rescored each case. Re ceiver operating characteristic (ROC) curves from both scoring session s were generated. The mean areas under the ROC curves for the entire g roup was 0.83 +/- 0.12 initially, and improved to 0.87 +/- 0.09 (p < 0 .05) after viewing prior chest radiographs. Receiver operating charact eristic curves of thoracic radiologists described greater areas than t hose of general radiologists both before and after viewing prior chest radiographs; 0.95 +/- 0.01 versus 0.78 +/- 0.08 (p < 0.05) and 96 +/- 0.02 versus 0.80 +/- 0.05 (p < 0.05). The mean sensitivity and specif icity of chest radiograph interpretation for HPS was 86 +/- 13% and 74 +/- 11%, respectively. Chest radiographs can differentiate HPS from A RDS. Accuracy is improved by the use of serial radiographs and more hi ghly trained readers. The chest radiograph findings may represent diff erences in the extent of alveolar epithelial dam age seen in HPS and A RDS.