A 26-year-old woman three weeks postpartum presents with severe headache, vomiting and a focal seizure. Contrast-enhanced CT head shows a filling defect surrounded by enhancing dura in the superior sagittal sinus. This finding is known as:

• A Empty delta sign ✓
• B Delta sign of pseudotumor cerebri
• C Spot sign
• D Pseudodelta sign of subdural empyema

Explanation

The empty delta sign is the classic contrast CT sign of superior sagittal sinus thrombosis: enhanced collateral veins and dura in the triangular cross section of the sinus surround a non-enhancing central thrombus, producing a hollow triangle. The spot sign refers to active extravasation within intracerebral hemorrhage, while the pseudodelta sign describes a hyperdense falx mimicking sinus pathology on unenhanced scans.

Reference: Grainger and Allison's Diagnostic Radiology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.