Aortic dissection in Siriraj patients: Computed tomography findings

Background: CTA has replaced angiography in both diagnosis and evaluation of aortic dissection. Most findings are associated with true and false lumens which account for the most important information in both diagnosis and management. Objective: To describe computed tomographic (CT) findings including types based on Stanford classification, true and false lumens, acute and chronic aortic dissections, relation to origins of aortic branches, complications and other related findings. Methods: Computed tomographic angiography (CTA) scans of one hundred and twenty patients with aortic dissection during 2007 to 2016 were retrospectively reviewed. The findings indicating types, true and false lumens, acute and chronic, origination of aortic branches, complication and other related findings are categorized. Result: Most true lumens were smaller, having outer wall calcification. Most false lumens were larger, showing beak sign, cobweb sign, and intraluminal thrombi. However, the larger lumens could be true lumens as well as the smaller lumen could be a false lumen and outer wall calcification could be seen in a false lumen. The larger true lumens and the smaller false lumens with outer wall calcifications were more often found in chronic aortic dissection than acute aortic dissection. Both acute and chronic aortic dissections were more Stanford type B than type A. Complications included rupture, hemopericardium, hemothorax, hemomediastinum and distal organ infarction, which were more frequent in acute dissection. Intrathoracic complications were more commonly caused by type A acute dissection. Renal infarction was the most common complication in type B acute aortic dissection. Conclusion: Most CT fi ndings of aortic dissection in this study were typical. Atypical fi ndings were also found in both acute and chronic aortic dissections. Outer wall calcifi cations of false lumens in acute aortic dissection were found in 2 cases.