Thoracic aortic pseudoaneurysm in the context of blunt chest trauma. Sagittal reconstruction of arterial phase MDCT demonstrates an abnormal contour of the thoracic aorta. A sacculation filled with iodinated contrast material involving the anterior aspect of transition of the aortic arch with the descending aorta, immediately after the emergency of the left subclavian artery, consistent with aortic pseudoaneurysm (arrow).