Pediatric Thoracic Aortic Injury

Etiology: Blunt thoracic trauma
Imaging CXR:
— Wide superior mediastinum
— Abnormal aortic contour
— Deviated endotracheal tube or nasogastric tube to right
— Depression of left mainstem bronchus
— Left pleural apical cap
— Left pneumothorax or pleural effusion
— Rib fracture
Note: Mediastinal / chest ratio > 0.25 on CXR at level of aortic arch should be investigated with CT
Imaging CT:
— 90% of injuries at aortic isthmus
— Periaortic hematoma
— Intimal flap
— Pseudoaneurysm
— Extravasation of contrast
DDX: Ductus diverticulum of patent ductus arteriosus, motion on non-gated CT exam
Complications:
Treatment:
Clinical: Uncommon in children

Radiology Cases of Thoracic Aortic Injury

CXR and CT of thoracic aortic injury — CXR AP (above left) shows a widened superior mediastinum. Axial CT with contrast of the chest shows an aortic laceration beginning at the level of aortic isthmus (above right) with a large amount of hemorrhage in the mediastinum which continues downward (below left) until the aorta is almost completely occluded by thrombus (below right).

CT of thoracic aortic injury — Axial CT with contrast of the chest at the level of the aortic arch (above left) shows a large amount of fluid in the superior mediastinum while subsequent lower slices (above right and below left) show an intimal flap in the descending aorta. Sagittal CT (below right) shows a pseudoaneurysmal dilation of the aorta beginning at the aortic isthmus.

CXR and CT and angiogram of thoracic aortic injury — CXR AP shows widened mediastinum. Axial CT with contrast of the chest shows dilated caliber of the thoracic aorta at the level of the diaphragm with surrounding mediastinal fluid (above) and normal caliber of the abdominal aorta with evidence of retrocrual hemorrhage tracking into the abdomen (below). Angiogram shows a pseudoaneurysm of the aorta at the level of the diaphragm.

Angiogram of thoracic aortic injury — Early (left) and late (right) images from an angiogram of the aorta show a focal aneurysmal dilation of the aorta which begins at the aortic isthmus.

Angiogram of pediatric thoracic aortic injury — Late image from an angiogram of the aorta shows a focal aneurysmal dilation of the aorta which begins near the aortic isthmus.

Radiology Cases of False Positive Thoracic Aortic Injury

CT of false positive thoracic aortic injury / aortic dissection — Non-gated axial (above left) and coronal (above right) CT with contrast of the chest show a line in the lumen of the aorta from the sinotubular junction to the origin of the brachiocephalic artery. Repeat gated axial (below left) and coronal (below right) CT with contrast of the chest show absence of the previously seen line in the lumen of the aorta from the sinotubular junction to the origin of the brachiocephalic artery.

Radiology Cases of Pleural Cap Without Thoracic Aortic Injury

CXR of rib fracture and pleural cap — CXR AP shows a discontinuity at the lateral aspect of the left second rib. There is a pleural cap at the apex of the left hemithorax.