The value of the left apical cap in the diagnosis of aortic rupture: a prospective and retrospective study.

The authors conducted a prospective and retrospective study of the radiographic findings in 45 patients with traumatic rupture of the aorta. In 7 cases, a left apical cap was the only clearly visible abnormality. In 11 cases a cap was present together with a poorly defined aortic knob, while in 13 cases both were seen along with mediastinal widening. In 14 cases, all of the classical signs of aortic rupture were present, but an apical cap was not seen or was not considered significant. Of 32 aortograms obtained, 12 were taken solely because of an apical cap; 2 were positive for aortic rupture and 10 were negative. No aortic rupture was found in patients with a left apical cap and fractures of the ribs, vertebral bodies, or scapulae.