What is the cause of the patient's chest and abdominal pain?
The aorta is abnormal and demonstrates an intramural haematoma.
What classification system can be used to help describe AIHs?
Stanford classification system: ~60% are type A and ~40% are type B.
What main abnormality is seen on both non-contrast and contrast-enhanced CT?
An enlarged aorta with aortic wall diameter > 7 mm.
What differentials can be considered?
Atheroma, thrombus, aortitis, retroperitoneal fibrosis, and periaortic lymphoma. The imaging features are usually sufficient to make a definitive diagnosis.
There is mural thickening of the aorta extending from the arch (at the origin of the subclavian artery) to just above the renal artery. This is predominantly along the superior wall of the arch and along the left posterolateral aspect in the thoracic descending aorta. The mural thickening is high density on the precontrast images.
There are pockets of contrast at various points within the mural thickening. A discrete intimal flap is not demonstrated except at the inferior extent of the mural thickening where there is the suggestion of a short segment flap. There was a tiny focus of mural enhancement on the previous study at this site. Maximum thoracic aortic diameter 3.8 cm.
There is also an 4.6 cm infrarenal fusiform abdominal aortic aneurysm extending to the bifurcation of the aorta with a 2.6 cm neck. Scattered calcific atheroma.
Conclusion:
1. The findings are consistent with aortic intramural haematoma (Type B).