X ray findings suggestive of thoracic aortic pathology
Primary signs include an enlarged or enlarging aorta, an indistinct aortic contour, or displacement of intimal atherosclerotic calcifications (in aortic dissection). Secondary signs, indicating mass effect from an aneurysm or hematoma, include mediastinal widening; displacement of adjacent structures such as the trachea, the left main stem bronchus, or a nasogastric tube in the esophagus; an “apical cap,” or mediastinal hematoma extending above the lung apex; or pleural or pericardial effusion (which can be hemorrhagic, but is more commonly due to exudative fluid secondary to the adjacent acute aortic process). Many of these findings are not specific for aortic pathologic conditions. Even mediastinal hematoma in the setting of trauma is not specific because it may be secondary to venous rather than arterial injury.