Periaortic air in native and post-operative aorta on computed tomography.

Periaortic air can be seen in various conditions which can be a benign imaging finding or harbinger of a catastrophic event. The causes vary in native aorta and post-operative aorta. A radiologist has an important part in the management process of these patients, as the treatment varies from conservative to radical surgery based on the aetiology. The presence of periaortic air seen in the light of various clinical, laboratory and radiological findings can guide the radiologist towards a particular aetiology. Cross-sectional imaging, mainly computed tomography, is an indispensable tool in recognising ectopic periaortic air and to identify the associated findings and eventually make an accurate diagnosis. We present a pictorial review of various causes of the periaortic air in native and postoperative aorta, the salient features and management of the described conditions.