or nearly all of the circumference of the aorta. Rupture is defined as a forcible disruption of tissue. Some disagree with the usage of rupture as they believe it implies that a tear is incompatible with life; however, the term accurately gauges the severity of tears in the aorta. A rupture can be either complete or partial, and can be classified further by the position of the tear. Imaging The gold standard for diagnosis of thoracic aortic injury is aortography. This method involves inserting a catheter into the aorta and directly injecting contrast material. The primary benefit of aortography is the ability to precisely determine the location of injury for surgical planning. Another imaging modality is CT angiogram which has a sensitivity of 100%. A CT angiogram relies on timing the CT scan after a bolus of IV contrast is administered from a peripheral IV site. Since a CT angiogram has a sensitivity of 100% and less invasive due to the peripheral placement of the IV line than aortagraphy it is the primary imaging choice. This allows visualization of the aorta and provides precise locations of traumatic injury. A CT angiogram does show both direct and indirect signs of aortic injury. The indirect sign that you can see is effacement of fat due to a hematoma. This sign should clue in a radiologist that there is an underlying injury. Some direct signs from a CT include having an intimal flap, irregularity of the shape of the aorta, filling defects secondary to a thrombus, or out pouching of the aorta. However, non contrasted CT scans, chest X-rays, and transesophageal echos can also be used. Chest X-rays most sensitive finding is a widened mediastinum of greater than 8 cm. An apical cap and displacement of the trachea to either side of the chest from midline can also be seen. A normal chest X-ray, however, does not exclude a diagnosis of thoracic aortic injury. A chest X-ray can also be useful to diagnose subsequent problems caused by aortic rupture such as pneumothorax or hemothorax. Non contrasted CT scans might show an intimal flap, periaortic hematoma, luminal filling defect, aortic contour abnormality, pseudoaneurysm, contained rupture, vessel wall disruption, active extravasation of intravenous contrast from the aorta and is therefore useful to assess for minimal aortic injury. Trans esophageal echos are useful in patients that are hemodynamically unstable, but the sensitivity and specificity of this