[Differential diagnosis of posttraumatic pulmonary infiltrates]

The differential diagnostic value of radio-morphological criteria as well as the prognostic fate of pulmonary infiltrates was studied in 377 patients presenting with major traumatic infiltrates in the thorax. We found that neither the character of the infiltrates (alveolar/interstitial) nor their morphology (homogeneous/inhomogeneous, dense/dispersed) were suitable for differentiation owing to extensive overlapping. The localization of infiltration, otherwise a good diagnostic indicator, provided little reliable information either. Conversely, the time course of the infiltrates, especially the time of their first visualization, turned out to be the only criterion usable for differentiation. Patients studied immediately after or within hours of an accident exhibited contusion and aspiration infiltrates, with a delay of 1-2 days the infiltrates were mostly caused by fat embolism and ARDS, while pneumonic infiltrates appeared after at least 2 days. The course of the infiltrates further permits certain diagnostic conclusions, but it is of little help in establishing the primary diagnosis and may be usable for corrections at best. The relatively high specificity of the criterion "first appearance of infiltrates" may be reduced by the coincidence of several lesions or ensuing complications. In retrospect, it seems that a reliable radiological differential diagnosis of posttraumatic infiltrates is not possible, but satisfactory results can be achieved if specific X-ray criteria are viewed against an extensive clinical back-ground.