Figure 20b. Rupture of Stanford type A typical aortic dissection. (a) Contrast-enhanced CT scan shows stenosis of the pulmonary arteries, which are enveloped in a hemorrhagic sheath. (b) Magnified view shows the detail of the stenosis around the left lower lobe pulmonary artery (arrows). (c) Scan at lung window setting shows areas of alveolar opacity in the right upper lobe caused by diffusion of blood through the peribronchovascular hilar sheath. (d) Posterior view of the autopsy specimen shows hemorrhage in the ascending aorta (arrows) and surrounding the pulmonary arteries (arrowheads). (e) Drawing provides a posterior view of the anatomic pathway from the ascending aorta to the pulmonary interstitium.