Abdominal aortic aneurysm: yin-yang sign
From the case:
Abdominal aortic aneurysm: yin-yang sign
CT
Axial C+ arterial phase
Contrast enhanced CT scan demonstrates the yin-yang sign in the aneurysm of abdominal aorta. The high density are represents the patent lumen whereas the low density area represents the mural thrombus.