Aortic injury: comparison of supine and upright portable chest films to evaluate the widened mediastinum.

Despite many reports of radiologic findings that may be suggestive of aortic injury, most authors believe the recognition of a widened mediastinum on chest film remains the sine qua non. Few studies have confirmed the widely held belief that the supine AP chest film is inaccurate in assessing the width of the mediastinal structures, and that one should use only the upright or sitting chest films. This study was undertaken to assess the accuracy of both upright and supine chest films in the evaluation of mediastinal widening after blunt deceleration chest injury. Both supine and upright sitting chest films were obtained immediately on arrival in the resuscitation areas for 55 patients. Twenty-one (38%) exhibited a mediastinum that appeared wide on supine view but within normal limits on the upright view, as attested by two radiologists. Aortography was not performed on any of these patients. Daily upright chest films, repeated until discharge, failed to demonstrate any change in mediastinal anatomy, and all patients recovered without incident. Twelve patients' films (22%) demonstrated widened mediastinum on both views, and these 12 patients underwent immediate aortography. Aortic rupture was revealed in four (33%). This study clarifies the diagnostic value of the upright chest film in assessing the mediastinum after blunt injury. It confirms the belief that supine films are not accurate, and that they may lead to numerous false positives and unnecessary aortograms. The initial upright or sitting chest film is accurate, and its use is cost-effective and time-saving for patient and physician.(ABSTRACT TRUNCATED AT 250 WORDS)