The density of the aortic wall corresponding blood density and not atheroscleros as it was misstaken the mass in the posterior mediastinal mass has the density of blood and proved to be blood, even on the right side. Intramural haematoma weakened the aorta and progressed to outward rupture of the aortic wall and bleeding in the mediastinum. It may have been caused by a penetrating atherosclerotic ulcer.
Patient died within two hours after CT.
Summary: acute deterioration plus intramural haemorrhage suggest that changes in the mediastinum and the pleura are most likely to be blood.