Double density sign (berry aneurysm)
Double density sign of berry aneurysms refers to the angiographic appearance of a small intracranial aneurysm projecting in front or behind a vessel of similar caliber. As such, the border of the aneurysm cannot easily be seen, but the extra contrast within it can be seen as a rounded area of increased density. A similar appearance can be generated by a branch coming toward or away from the image intensifier.
See also
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