Accuracy of radiographic differentiation of bacterial from nonbacterial pneumonia.

The chest roentgenogram is an accepted tool for the diagnosis of pneumonia. Little information is available, however, addressing the ability of physicians to distinguish bacterial from nonbacterial pneumonias by examination of the chest roentgenogram. Five different observers evaluated 36 chest films from patients with pneumonia who had a laboratory proven etiologic diagnosis. The sensitivity of roentgenogram diagnosis of bacterial pneumonia ranged from 42-58 percent. When clinical and laboratory data were provided to the observers the sensitivity ranged from 42-92 percent. This study indicates that chest film examination is too insensitive to be useful for the selection of patients who have bacterial pneumonia from those whose pneumonia is non-bacterial.