Comparison of mediastinal width, mediastinal-thoracic and -cardiac ratios, and "mediastinal widening" in detection of traumatic aortic rupture.
This study was undertaken to determine whether direct measurement of mediastinal width or computation of ratios of measurements of easily detectable mediastinal structures is more effective than the subjective impression of "mediastinal widening" in selecting trauma patients for aortography. A group of five surgeons and radiologists individually read in blinded fashion 149 chest films of trauma victims who had undergone aortography to rule out traumatic rupture of the aorta (TRA). Each made a subjective interpretation of "mediastinal widening," as well as direct measurement of mediastinal width (MW), thoracic width at the level of the mediastinum, cardiac width, and maximum thoracic width. Mediastinal-cardiac (MC), mediastinal-thoracic (MT), and mediastinal-mediastinothoracic (MMT) ratios were calculated. Statistically significant differences were found in all parameters of direct measurement between cases with and without TRA (P from .0001 for MT to .01 for MMT). The critical measurement for mediastinal width separating positive from negative cases was 8.0 cm; the critical ratios were MT = 0.275, MC = 0.555, and MMT = 0.36. Application of these parameters to detect TRA yielded sensitivities of .75 for MW, .68 for MC, .66 for MMT, and .62 for MT. Statistically significant differences between observers' measurements were seen. None of these measurements was as effective as subjective interpretation of mediastinal widening, which had a sensitivity of .91 (P = .0000). We conclude that the subjective impression of mediastinal widening is superior to "objective" direct measurement of mediastinal structures for identification of trauma patients with aortic rupture.
D001011:Aorta / Q000293:injuries; D001019:Aortic Rupture / Q000000981:diagnostic imaging*; D001027:Aortography; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D008482:Mediastinum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic; D013909:Thorax / Q000033:anatomy & histology*