Fig. 5

Sketch shows the postulation of the development of broken-crescent sign in CT. a Acute aortic IMH with typical hyper-attenuating crescentic hematoma along the aorta on axial CT. b Partial aortic adventitial tear with outward seepage of the hematoma (curve arrow), leading to a broken-crescent configuration (arrows). Focal out-bulging (open arrow) of the residual inner aortic wall results in temporary sealing of the underlying adventitial defect. c Rupture of the aorta through the weakened residual inner aortic wall (curve arrow) with partially collapsed aorta