Bib Sign in Proximal Descending Thoracic Aorta Rupture on CT Angiography: Presentation of a Paradigmatic Case

Figure 3

Unenhanced CT images showing the obliterated anterior descending aortic and paraesophageal fat due to hyperattenuating fluid collection (red arrowhead in (a)). The fluid flowed anteriorly through the extrapericardial inlet, under the left branch of the pulmonary artery, and above the left pericardial pulmonic recess of transverse sinus (green arrowhead in (a)). The fluid reached the anterior surface of the pericardial sac, between the prevascular and visceral mediastinal compartments (yellow arrowheads in (a–c) and (g–i)), and then flowed out caudally, covering the anterior wall of the right ventricle (yellow arrowheads in (f)), as a sort of “bib” on the heart (j). No associated pericardial effusion (red arrowheads in (d)). High-attenuation extrapericardial fluid (average 31 HU) consistent with hemomediastinum (e).

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