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What is Delta-sign is seen in and explain in detail?
Delta-sign is seen in sigmoid sinus thrombosis. Contrast-enhanced CT scan can show sinus thrombosis by typical delta sign. It is a triangular area with rim enhancement, and the central low-density area is seen in a posterior cranial fossa on axial cuts. "Delta sign" may also be seen on contrast-enhanced MRI. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 92,93)