Thrombus fissuration sign (aortic aneurysm)

Thrombus fissuration is a sign of impending rupture of an aortic aneurysm. It reflects blood dissecting into the intramural thrombus. This sign is observed on contrast-enhanced CT as a linear contrast infiltration from the aneurysm lumen through the intramural thrombus. Thrombus fissurations extending from the aortic lumen to the aneurysm wall indicate increase in the wall tension and impending rupture of an abdominal aortic aneurysm.